DinnerNow http://www.dinnernow.net is a .NET 3.0 sample application. I heard about it on ArcCast (http://channel9.msdn.com/shows/ARCast_with_Ron_Jacobs).
DinnerNow is an interesting application taking advantage of most of .NET 3.0 Windows Foundations (i.e. WCF, WPF, etc) and the source code is available for download. I want to download the source code and play with it over the weekend and familiarise with those kinds of technologies.