Discover a New WCF with Discovery!
Juval Lowy has a great article in the January 2010 issue of MSDN Magazine: Discover a New WCF with Discovery. He goes into the basics of Discovery, how it works and why you would use it, and also provides his own set of helper classes that you can download to make using discovery in your application even easier. Then he shows how to use these classes to build a publish-subscribe service using WCF.