ASP.NET MVC: Controlling serialization of property names with JsonResult

I wanted something a bit more baked into the framework than what Jarrett suggested, so here's what I did:

JsonDataContractActionResult:

public class JsonDataContractActionResult : ActionResult
{
    public JsonDataContractActionResult(Object data)
    {
        this.Data = data;
    }

    public Object Data { get; private set; }

    public override void ExecuteResult(ControllerContext context)
    {
        var serializer = new DataContractJsonSerializer(this.Data.GetType());
        String output = String.Empty;
        using (var ms = new MemoryStream())
        {
            serializer.WriteObject(ms, this.Data);
            output = Encoding.Default.GetString(ms.ToArray());
        }
        context.HttpContext.Response.ContentType = "application/json";
        context.HttpContext.Response.Write(output);
    }
}

JsonContract() method, added to my base controller class:

    public ActionResult JsonContract(Object data)
    {
        return new JsonDataContractActionResult(data);
    }

Sample Usage:

    public ActionResult Update(String id, [Bind(Exclude="Id")] Advertiser advertiser)
    {
        Int32 advertiserId;
        if (Int32.TryParse(id, out advertiserId))
        {
            // update
        }
        else
        {
            // insert
        }

        return JsonContract(advertiser);
    }

Note: If you're looking for something more performant than JsonDataContractSerializer, you can do the same thing using JSON.NET instead. While JSON.NET doesn't appear to utilize DataMemberAttribute, it does have its own JsonPropertyAttribute which can be used to accomplish the same thing.

Here's my implementation of Daniel Schaffer's answer, with the suggested improvements by Justin Rusbatch and Daniel incorporated.

using System;
using System.Runtime.Serialization.Json;
using System.Web.Mvc;

public class JsonDataContractActionResult : JsonResult
{
    public JsonDataContractActionResult( Object data )
    {
        this.Data = data;
    }

    public override void ExecuteResult( ControllerContext context )
    {
        var serializer = new DataContractJsonSerializer( this.Data.GetType() );
        context.HttpContext.Response.ContentType = "application/json";
        serializer.WriteObject( context.HttpContext.Response.OutputStream, 
            this.Data );
    }
}