gistfile1.cs

[ServiceContract]

public class DocumentResource
{

    [WebGet(UriTemplate="{name}")]
    public Document Get(string name, HttpResponseMessage resp)
    {

        Document doc;
        //foo has moved
        if (name == "Foo")
        {
            resp.StatusCode = HttpStatusCode.MovedPermanently;
            resp.Headers.Location = new Uri("http://someplace/Foo");
            return null;
        }

        //find the document
        return doc;
    }
}