MVC Silverlight passing user context

I've got a MVC / Silverlight a开发者_如何学Gopp and now need to begin passing data back and forward between the two. I've created a domainservice in my MVC project, but my question is regarding user context and authentication. What is the best way to handle this? In non MVC Silverlight projects I used to pass user ids etc in params.

Any guidance would be greatly appreciated.

Thanks.

---

In the end I found this site and used this method: http://www.global-webnet.net/blogengine/post/2009/11/17/ASPNET-MVC-2-Passing-Parameters-to-Silverlight-application.aspx

Hope this helps someone else.