OpenID Enables P2P SIP
This is a rather cool development, not only for people trying to implement peer-2-peer SIP, but for proponents of OpenID. The method Aswath Rao proposes would actually eliminate one of the major issues with most P2p systems–the dreaded supernode. The OpenID server would serve as the clearinghouse for NAT-related information, thus allowing the bulk of the traffic to truly be P2p.
The question, of course, is how effective it will be at overcoming the various forms of NAT. However, Aswath is one smart dude and if anyone can figure this out, he can.