diff --git a/Src/Newtonsoft.Json.Tests/JsonConvertTest.cs b/Src/Newtonsoft.Json.Tests/JsonConvertTest.cs
index f1348c22..01bfb474 100644
--- a/Src/Newtonsoft.Json.Tests/JsonConvertTest.cs
+++ b/Src/Newtonsoft.Json.Tests/JsonConvertTest.cs
@@ -24,11 +24,18 @@
 #endregion
 
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Runtime.Serialization;
 using System.Text;
+#if !(NET20 || NET35 || SILVERLIGHT)
+using System.Threading.Tasks;
+#endif
 using System.Xml;
 using Newtonsoft.Json.Converters;
+using Newtonsoft.Json.Linq;
+using Newtonsoft.Json.Tests.Serialization;
+using Newtonsoft.Json.Tests.TestObjects;
 using Newtonsoft.Json.Utilities;
 using NUnit.Framework;
 
@@ -640,5 +647,78 @@ now brown cow?", '"', true);
 
       return (T)converter.ReadJson(reader, typeof(T), null, null);
     }
+
+#if !(NET20 || NET35 || SILVERLIGHT)
+    [Test]
+    public void Async()
+    {
+      Task<string> task = null;
+      
+      task = JsonConvert.SerializeObjectAsync(42);
+      task.Wait();
+
+      Assert.AreEqual("42", task.Result);
+
+      task = JsonConvert.SerializeObjectAsync(new[] {1, 2, 3, 4, 5}, Formatting.Indented);
+      task.Wait();
+
+      Assert.AreEqual(@"[
+  1,
+  2,
+  3,
+  4,
+  5
+]", task.Result);
+
+      task = JsonConvert.SerializeObjectAsync(DateTime.MaxValue, Formatting.None, new JsonSerializerSettings
+        {
+          DateFormatHandling = DateFormatHandling.MicrosoftDateFormat
+        });
+      task.Wait();
+
+      Assert.AreEqual(@"""\/Date(253402300799999)\/""", task.Result);
+
+      var taskObject = JsonConvert.DeserializeObjectAsync("[]");
+      taskObject.Wait();
+
+      Assert.AreEqual(new JArray(), taskObject.Result);
+
+      Task<object> taskVersionArray = JsonConvert.DeserializeObjectAsync("['2.0']", typeof(Version[]), new JsonSerializerSettings
+        {
+          Converters = {new VersionConverter()}
+        });
+      taskVersionArray.Wait();
+
+      Version[] versionArray = (Version[])taskVersionArray.Result;
+
+      Assert.AreEqual(1, versionArray.Length);
+      Assert.AreEqual(2, versionArray[0].Major);
+
+      Task<int> taskInt = JsonConvert.DeserializeObjectAsync<int>("5");
+      taskInt.Wait();
+
+      Assert.AreEqual(5, taskInt.Result);
+
+      var taskVersion = JsonConvert.DeserializeObjectAsync<Version>("'2.0'", new JsonSerializerSettings
+        {
+          Converters = {new VersionConverter()}
+        });
+      taskVersion.Wait();
+
+      Assert.AreEqual(2, taskVersion.Result.Major);
+
+      Movie p = new Movie();
+      p.Name = "Existing,";
+
+      Task taskVoid = JsonConvert.PopulateObjectAsync("{'Name':'Appended'}", p, new JsonSerializerSettings
+      {
+        Converters = new List<JsonConverter> { new JsonSerializerTest.StringAppenderConverter() }
+      });
+
+      taskVoid.Wait();
+
+      Assert.AreEqual("Existing,Appended", p.Name);
+    }
+#endif
   }
 }
\ No newline at end of file
diff --git a/Src/Newtonsoft.Json.Tests/PerformanceTests.cs b/Src/Newtonsoft.Json.Tests/PerformanceTests.cs
index ca928597..57c9e8eb 100644
--- a/Src/Newtonsoft.Json.Tests/PerformanceTests.cs
+++ b/Src/Newtonsoft.Json.Tests/PerformanceTests.cs
@@ -704,7 +704,6 @@ namespace Newtonsoft.Json.Tests
     }
 
     [Test]
-    [Ignore]
     public void NestedJToken()
     {
       Stopwatch sw;
@@ -717,7 +716,7 @@ namespace Newtonsoft.Json.Tests
         for (int j = 0; j < i; j++)
         {
           JArray temp = new JArray();
-          ija.Add(temp);
+          ija.AddAndSkipParentCheck(temp);
           ija = temp;
         }
         ija.Add(1);
@@ -727,26 +726,21 @@ namespace Newtonsoft.Json.Tests
     }
 
     [Test]
-    [Ignore]
-    public void NestedXElement()
+    public void DeserializeNestedJToken()
     {
+      string json = (new string('[', 100000)) + "1" + ((new string(']', 100000)));
+
       Stopwatch sw;
-      for (int i = 10000; i <= 100000; i += 10000)
-      {
-        sw = new Stopwatch();
-        sw.Start();
-        XElement ija = new XElement("root");
-        XElement ijt = ija;
-        for (int j = 0; j < i; j++)
-        {
-          XElement temp = new XElement("child");
-          ija.Add(temp);
-          ija = temp;
-        }
-        ija.Add(1);
-        sw.Stop();
-        Console.WriteLine("Created a XElement of depth {0} (using OM) in {1} millis", i, sw.ElapsedMilliseconds);
-      }
+      sw = new Stopwatch();
+      sw.Start();
+
+      var a = (JArray)JsonConvert.DeserializeObject(json);
+
+      sw.Stop();
+
+      Assert.AreEqual(1, a.Count);
+      
+      Console.WriteLine("Deserialize big ass nested array in {0} millis", sw.ElapsedMilliseconds);
     }
   }
 
diff --git a/Src/Newtonsoft.Json.Tests/Properties/AssemblyInfo.cs b/Src/Newtonsoft.Json.Tests/Properties/AssemblyInfo.cs
index e5c19f66..7920d374 100644
--- a/Src/Newtonsoft.Json.Tests/Properties/AssemblyInfo.cs
+++ b/Src/Newtonsoft.Json.Tests/Properties/AssemblyInfo.cs
@@ -72,5 +72,5 @@ using System.Security;
 // by using the '*' as shown below:
 [assembly: AssemblyVersion("4.0.8.0")]
 #if !PocketPC
-[assembly: AssemblyFileVersion("4.0.8.14704")]
+[assembly: AssemblyFileVersion("4.0.8.14707")]
 #endif
diff --git a/Src/Newtonsoft.Json/JsonConvert.cs b/Src/Newtonsoft.Json/JsonConvert.cs
index 5682f8e7..33689def 100644
--- a/Src/Newtonsoft.Json/JsonConvert.cs
+++ b/Src/Newtonsoft.Json/JsonConvert.cs
@@ -26,6 +26,9 @@
 using System;
 using System.IO;
 using System.Globalization;
+#if !(NET20 || NET35 || SILVERLIGHT)
+using System.Threading.Tasks;
+#endif
 using Newtonsoft.Json.Utilities;
 using System.Xml;
 using Newtonsoft.Json.Converters;
@@ -643,6 +646,7 @@ namespace Newtonsoft.Json
       return IsJsonPrimitiveTypeCode(Type.GetTypeCode(type));
     }
 
+    #region Serialize
     /// <summary>
     /// Serializes the specified object to a JSON string.
     /// </summary>
@@ -733,6 +737,50 @@ namespace Newtonsoft.Json
       return sw.ToString();
     }
 
+#if !(NET20 || NET35 || SILVERLIGHT)
+    /// <summary>
+    /// Asynchronously serializes the specified object to a JSON string using a collection of <see cref="JsonConverter"/>.
+    /// </summary>
+    /// <param name="value">The object to serialize.</param>
+    /// <returns>
+    /// A task that represents the asynchronous serialize operation. The value of the <c>TResult</c> parameter contains a JSON string representation of the object.
+    /// </returns>
+    public static Task<string> SerializeObjectAsync(object value)
+    {
+      return SerializeObjectAsync(value, Formatting.None, null);
+    }
+
+    /// <summary>
+    /// Asynchronously serializes the specified object to a JSON string using a collection of <see cref="JsonConverter"/>.
+    /// </summary>
+    /// <param name="value">The object to serialize.</param>
+    /// <param name="formatting">Indicates how the output is formatted.</param>
+    /// <returns>
+    /// A task that represents the asynchronous serialize operation. The value of the <c>TResult</c> parameter contains a JSON string representation of the object.
+    /// </returns>
+    public static Task<string> SerializeObjectAsync(object value, Formatting formatting)
+    {
+      return SerializeObjectAsync(value, formatting, null);
+    }
+
+    /// <summary>
+    /// Asynchronously serializes the specified object to a JSON string using a collection of <see cref="JsonConverter"/>.
+    /// </summary>
+    /// <param name="value">The object to serialize.</param>
+    /// <param name="formatting">Indicates how the output is formatted.</param>
+    /// <param name="settings">The <see cref="JsonSerializerSettings"/> used to serialize the object.
+    /// If this is null, default serialization settings will be is used.</param>
+    /// <returns>
+    /// A task that represents the asynchronous serialize operation. The value of the <c>TResult</c> parameter contains a JSON string representation of the object.
+    /// </returns>
+    public static Task<string> SerializeObjectAsync(object value, Formatting formatting, JsonSerializerSettings settings)
+    {
+      return Task.Factory.StartNew(() => SerializeObject(value, formatting, settings));
+    }
+#endif
+    #endregion
+
+    #region Deserialize
     /// <summary>
     /// Deserializes the JSON to a .NET object.
     /// </summary>
@@ -868,6 +916,68 @@ namespace Newtonsoft.Json
       return deserializedValue;
     }
 
+#if !(NET20 || NET35 || SILVERLIGHT)
+    /// <summary>
+    /// Asynchronously deserializes the JSON to the specified .NET type.
+    /// </summary>
+    /// <typeparam name="T">The type of the object to deserialize to.</typeparam>
+    /// <param name="value">The JSON to deserialize.</param>
+    /// <returns>
+    /// A task that represents the asynchronous deserialize operation. The value of the <c>TResult</c> parameter contains the deserialized object from the JSON string.
+    /// </returns>
+    public static Task<T> DeserializeObjectAsync<T>(string value)
+    {
+      return DeserializeObjectAsync<T>(value, null);
+    }
+
+    /// <summary>
+    /// Asynchronously deserializes the JSON to the specified .NET type.
+    /// </summary>
+    /// <typeparam name="T">The type of the object to deserialize to.</typeparam>
+    /// <param name="value">The JSON to deserialize.</param>
+    /// <param name="settings">
+    /// The <see cref="JsonSerializerSettings"/> used to deserialize the object.
+    /// If this is null, default serialization settings will be is used.
+    /// </param>
+    /// <returns>
+    /// A task that represents the asynchronous deserialize operation. The value of the <c>TResult</c> parameter contains the deserialized object from the JSON string.
+    /// </returns>
+    public static Task<T> DeserializeObjectAsync<T>(string value, JsonSerializerSettings settings)
+    {
+      return Task.Factory.StartNew(() => DeserializeObject<T>(value, settings));
+    }
+
+    /// <summary>
+    /// Asynchronously deserializes the JSON to the specified .NET type.
+    /// </summary>
+    /// <param name="value">The JSON to deserialize.</param>
+    /// <returns>
+    /// A task that represents the asynchronous deserialize operation. The value of the <c>TResult</c> parameter contains the deserialized object from the JSON string.
+    /// </returns>
+    public static Task<object> DeserializeObjectAsync(string value)
+    {
+      return DeserializeObjectAsync(value, null, null);
+    }
+
+    /// <summary>
+    /// Asynchronously deserializes the JSON to the specified .NET type.
+    /// </summary>
+    /// <param name="value">The JSON to deserialize.</param>
+    /// <param name="type">The type of the object to deserialize to.</param>
+    /// <param name="settings">
+    /// The <see cref="JsonSerializerSettings"/> used to deserialize the object.
+    /// If this is null, default serialization settings will be is used.
+    /// </param>
+    /// <returns>
+    /// A task that represents the asynchronous deserialize operation. The value of the <c>TResult</c> parameter contains the deserialized object from the JSON string.
+    /// </returns>
+    public static Task<object> DeserializeObjectAsync(string value, Type type, JsonSerializerSettings settings)
+    {
+      return Task.Factory.StartNew(() => DeserializeObject(value, type, settings));
+    }
+#endif
+    #endregion
+
     /// <summary>
     /// Populates the object with values from the JSON string.
     /// </summary>
@@ -878,7 +988,6 @@ namespace Newtonsoft.Json
       PopulateObject(value, target, null);
     }
 
-
     /// <summary>
     /// Populates the object with values from the JSON string.
     /// </summary>
@@ -902,6 +1011,25 @@ namespace Newtonsoft.Json
       }
     }
 
+#if !(NET20 || NET35 || SILVERLIGHT)
+    /// <summary>
+    /// Asynchronously populates the object with values from the JSON string.
+    /// </summary>
+    /// <param name="value">The JSON to populate values from.</param>
+    /// <param name="target">The target object to populate values onto.</param>
+    /// <param name="settings">
+    /// The <see cref="JsonSerializerSettings"/> used to deserialize the object.
+    /// If this is null, default serialization settings will be is used.
+    /// </param>
+    /// <returns>
+    /// A task that represents the asynchronous populate operation.
+    /// </returns>
+    public static Task PopulateObjectAsync(string value, object target, JsonSerializerSettings settings)
+    {
+      return Task.Factory.StartNew(() => PopulateObject(value, target, settings));
+    }
+#endif
+
 #if !SILVERLIGHT
     /// <summary>
     /// Serializes the XML node to a JSON string.
diff --git a/Src/Newtonsoft.Json/JsonTextReader.cs b/Src/Newtonsoft.Json/JsonTextReader.cs
index f4091756..c7ffa80c 100644
--- a/Src/Newtonsoft.Json/JsonTextReader.cs
+++ b/Src/Newtonsoft.Json/JsonTextReader.cs
@@ -159,11 +159,13 @@ namespace Newtonsoft.Json
 
     private bool ParseDateIso(string text)
     {
+      const string isoDateFormat = "yyyy-MM-ddTHH:mm:ss.FFFFFFFK";
+
 #if !NET20
       if (_readType == ReadType.ReadAsDateTimeOffset)
       {
         DateTimeOffset dateTimeOffset;
-        if (DateTimeOffset.TryParseExact(text, "yyyy-MM-ddTHH:mm:ss.FFFFFFFK", CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out dateTimeOffset))
+        if (DateTimeOffset.TryParseExact(text, isoDateFormat, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out dateTimeOffset))
         {
           SetToken(JsonToken.Date, dateTimeOffset);
           return true;
@@ -173,7 +175,7 @@ namespace Newtonsoft.Json
 #endif
       {
         DateTime dateTime;
-        if (DateTime.TryParseExact(text, "yyyy-MM-ddTHH:mm:ss.FFFFFFFK", CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out dateTime))
+        if (DateTime.TryParseExact(text, isoDateFormat, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out dateTime))
         {
           dateTime = JsonConvert.EnsureDateTime(dateTime, DateTimeZoneHandling);
 
diff --git a/Src/Newtonsoft.Json/Linq/JArray.cs b/Src/Newtonsoft.Json/Linq/JArray.cs
index 3705a8d8..da7d2a0d 100644
--- a/Src/Newtonsoft.Json/Linq/JArray.cs
+++ b/Src/Newtonsoft.Json/Linq/JArray.cs
@@ -247,7 +247,7 @@ namespace Newtonsoft.Json.Linq
     /// <exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.IList`1"/> is read-only.</exception>
     public void Insert(int index, JToken item)
     {
-      InsertItem(index, item);
+      InsertItem(index, item, false);
     }
 
     /// <summary>
diff --git a/Src/Newtonsoft.Json/Linq/JContainer.cs b/Src/Newtonsoft.Json/Linq/JContainer.cs
index 01bda6e7..d1f83e0d 100644
--- a/Src/Newtonsoft.Json/Linq/JContainer.cs
+++ b/Src/Newtonsoft.Json/Linq/JContainer.cs
@@ -261,7 +261,7 @@ namespace Newtonsoft.Json.Linq
       return (content is IEnumerable && !(content is string) && !(content is JToken) && !(content is byte[]));
     }
 
-    internal JToken EnsureParentToken(JToken item)
+    internal JToken EnsureParentToken(JToken item, bool skipParentCheck)
     {
       if (item == null)
         return new JValue((object) null);
@@ -273,14 +273,18 @@ namespace Newtonsoft.Json.Linq
       else
       {
         // check whether attempting to add a token to itself
-        JContainer parent = this;
-        while (parent.Parent != null)
+        // not possible with a value, only a container
+        if (item is JContainer && !skipParentCheck)
         {
-          parent = parent.Parent;
-        }
-        if (item == parent)
-        {
-          item = item.CloneToken();
+          JContainer parent = this;
+          while (parent.Parent != null)
+          {
+            parent = parent.Parent;
+          }
+          if (item == parent)
+          {
+            item = item.CloneToken();
+          }
         }
       }
       return item;
@@ -309,14 +313,14 @@ namespace Newtonsoft.Json.Linq
       return ChildrenTokens.IndexOf(item, JTokenReferenceEqualityComparer.Instance);
     }
 
-    internal virtual void InsertItem(int index, JToken item)
+    internal virtual void InsertItem(int index, JToken item, bool skipParentCheck)
     {
       if (index > ChildrenTokens.Count)
         throw new ArgumentOutOfRangeException("index", "Index must be within the bounds of the List.");
 
       CheckReentrancy();
 
-      item = EnsureParentToken(item);
+      item = EnsureParentToken(item, skipParentCheck);
 
       JToken previous = (index == 0) ? null : ChildrenTokens[index - 1];
       // haven't inserted new token yet so next token is still at the inserting index
@@ -409,7 +413,7 @@ namespace Newtonsoft.Json.Linq
 
       CheckReentrancy();
 
-      item = EnsureParentToken(item);
+      item = EnsureParentToken(item, false);
 
       ValidateToken(item, existing);
 
@@ -523,7 +527,12 @@ namespace Newtonsoft.Json.Linq
     /// <param name="content">The content to be added.</param>
     public virtual void Add(object content)
     {
-      AddInternal(ChildrenTokens.Count, content);
+      AddInternal(ChildrenTokens.Count, content, false);
+    }
+
+    internal void AddAndSkipParentCheck(JToken token)
+    {
+      AddInternal(ChildrenTokens.Count, token, true);
     }
 
     /// <summary>
@@ -532,10 +541,10 @@ namespace Newtonsoft.Json.Linq
     /// <param name="content">The content to be added.</param>
     public void AddFirst(object content)
     {
-      AddInternal(0, content);
+      AddInternal(0, content, false);
     }
 
-    internal void AddInternal(int index, object content)
+    internal void AddInternal(int index, object content, bool skipParentCheck)
     {
       if (IsMultiContent(content))
       {
@@ -544,7 +553,7 @@ namespace Newtonsoft.Json.Linq
         int multiIndex = index;
         foreach (object c in enumerable)
         {
-          AddInternal(multiIndex, c);
+          AddInternal(multiIndex, c, skipParentCheck);
           multiIndex++;
         }
       }
@@ -552,7 +561,7 @@ namespace Newtonsoft.Json.Linq
       {
         JToken item = CreateFromContent(content);
 
-        InsertItem(index, item);
+        InsertItem(index, item, skipParentCheck);
       }
     }
 
@@ -745,7 +754,7 @@ namespace Newtonsoft.Json.Linq
 
     void IList<JToken>.Insert(int index, JToken item)
     {
-      InsertItem(index, item);
+      InsertItem(index, item, false);
     }
 
     void IList<JToken>.RemoveAt(int index)
@@ -831,7 +840,7 @@ namespace Newtonsoft.Json.Linq
 
     void IList.Insert(int index, object value)
     {
-      InsertItem(index, EnsureValue(value));
+      InsertItem(index, EnsureValue(value), false);
     }
 
     bool IList.IsFixedSize
diff --git a/Src/Newtonsoft.Json/Linq/JObject.cs b/Src/Newtonsoft.Json/Linq/JObject.cs
index 0478d2c3..13ca2fdc 100644
--- a/Src/Newtonsoft.Json/Linq/JObject.cs
+++ b/Src/Newtonsoft.Json/Linq/JObject.cs
@@ -146,13 +146,13 @@ namespace Newtonsoft.Json.Linq
       return (t != null && ContentsEqual(t));
     }
 
-    internal override void InsertItem(int index, JToken item)
+    internal override void InsertItem(int index, JToken item, bool skipParentCheck)
     {
       // don't add comments to JObject, no name to reference comment by
       if (item != null && item.Type == JTokenType.Comment)
         return;
 
-      base.InsertItem(index, item);
+      base.InsertItem(index, item, skipParentCheck);
     }
 
     internal override void ValidateToken(JToken o, JToken existing)
diff --git a/Src/Newtonsoft.Json/Linq/JProperty.cs b/Src/Newtonsoft.Json/Linq/JProperty.cs
index 3487ab10..44568184 100644
--- a/Src/Newtonsoft.Json/Linq/JProperty.cs
+++ b/Src/Newtonsoft.Json/Linq/JProperty.cs
@@ -78,7 +78,7 @@ namespace Newtonsoft.Json.Linq
 
         if (ChildrenTokens.Count == 0)
         {
-          InsertItem(0, newValue);
+          InsertItem(0, newValue, false);
         }
         else
         {
@@ -132,12 +132,12 @@ namespace Newtonsoft.Json.Linq
       throw new Exception("Cannot add or remove items from {0}.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
     }
 
-    internal override void InsertItem(int index, JToken item)
+    internal override void InsertItem(int index, JToken item, bool skipParentCheck)
     {
       if (Value != null)
         throw new Exception("{0} cannot have multiple values.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
 
-      base.InsertItem(0, item);
+      base.InsertItem(0, item, false);
     }
 
     internal override bool ContainsItem(JToken item)
diff --git a/Src/Newtonsoft.Json/Linq/JToken.cs b/Src/Newtonsoft.Json/Linq/JToken.cs
index 019fbc1e..15cb4a97 100644
--- a/Src/Newtonsoft.Json/Linq/JToken.cs
+++ b/Src/Newtonsoft.Json/Linq/JToken.cs
@@ -167,7 +167,7 @@ namespace Newtonsoft.Json.Linq
         throw new InvalidOperationException("The parent is missing.");
 
       int index = _parent.IndexOfItem(this);
-      _parent.AddInternal(index + 1, content);
+      _parent.AddInternal(index + 1, content, false);
     }
 
     /// <summary>
@@ -180,7 +180,7 @@ namespace Newtonsoft.Json.Linq
         throw new InvalidOperationException("The parent is missing.");
 
       int index = _parent.IndexOfItem(this);
-      _parent.AddInternal(index, content);
+      _parent.AddInternal(index, content, false);
     }
 
     /// <summary>
diff --git a/Src/Newtonsoft.Json/Linq/JTokenWriter.cs b/Src/Newtonsoft.Json/Linq/JTokenWriter.cs
index d5875393..ccc02b86 100644
--- a/Src/Newtonsoft.Json/Linq/JTokenWriter.cs
+++ b/Src/Newtonsoft.Json/Linq/JTokenWriter.cs
@@ -81,7 +81,7 @@ namespace Newtonsoft.Json.Linq
       if (_parent == null)
         _token = container;
       else
-        _parent.Add(container);
+        _parent.AddAndSkipParentCheck(container);
 
       _parent = container;
     }
diff --git a/Src/Newtonsoft.Json/Properties/AssemblyInfo.cs b/Src/Newtonsoft.Json/Properties/AssemblyInfo.cs
index 32ff8a28..73df4a05 100644
--- a/Src/Newtonsoft.Json/Properties/AssemblyInfo.cs
+++ b/Src/Newtonsoft.Json/Properties/AssemblyInfo.cs
@@ -85,7 +85,7 @@ using System.Security;
 // by using the '*' as shown below:
 [assembly: AssemblyVersion("4.0.8.0")]
 #if !PocketPC
-[assembly: AssemblyFileVersion("4.0.8.14704")]
+[assembly: AssemblyFileVersion("4.0.8.14707")]
 #endif
 
 [assembly: CLSCompliant(true)]