Kevin Hoffman is a big fan of the Windows P2P technologies, and he's writing a series of P2P blog posts.  Check out his latest post on PNRP ...

http://dotnetaddict.dotnetdevelopersjournal.com/peerseries_pnrp_intro.htm

...and don't miss his article about the WCF Peer Channel ..

http://dotnetaddict.dotnetdevelopersjournal.com/peerseries_wcfpeerchannel.htm

-Tyler