In this blog post Shawn Wildermuth introduces ADO.NET Data Services 1.5.
I've been teaching and using ADO.NET Data Services for a long time and I like showing off exposing a LINQ-based provider (Entity Framework, NHibernate or others) to a Silverlight application. While ADO.NET Data Services does expose its API through a REST API, the magic for me is in its use in Silverlight.