P2P Programming with WCF and .NET v3.5
My article on P2P programming with WCF and .NET v3.5 was finally published on MSDN. This was written a few months ago and has been going through the internal process at MS to get published- finally it is up there - better late than never I guess. 
I discuss the new features for P2P programming in WCF and .NET 3.5 and how things have moved up the stack in being a first class managed citizen now as opposed to you. Although the code was build and run on Vista you can run most of it on XP; however some elements such as PNM, Contacts and Collaboration are Vista specific.
Interestingly, you cannot download the source code for the samples and the small app that I had written - you can see the screen shots and the code snipped. If you need the complete solution let me know.