This is really old news, but something I didn't realize until last night at a Silverlight users group meeting.
Silverlight 2.0 brought us LINQ-to-Objects and LINQ-to-XML on the client. Bravo, yay, etc., but obviously LINQ-to-SQL was out of the question because you can't make an Internet-based T-SQL connection (i.e. over port 1433), for obvious reasons (*cough* security).
But Service Pack 1 for Visual Studio 2008, which introduced ADO.NET Data Services, also brought in along with it transparent LINQ-to-SQL support over WCF. This to me is bizzare. I haven't tried it, I only heard it mentioned. Frankly I'm worried about security, still, as it sounds a lot like RDO (Remote Data Objects) from back in the ASP Classic / ActiveX days, and which turned out to be a huge security disaster. Nonetheless, I'm still curious about how this might work securely and how it might make the workflow of a modern-age developer much, MUCH more pleasant than manually wiring up WCF for data synchronization to begin with.