Openid

James Henstridge » OpenID Attribute Exchange

http://blogs.gnome.org/jamesh/2007/11/26/openid-ax/ notes about what is Attribute Exchange (ax) in OpenID

Plaxo » A Recipe for OpenID-Enabling Your Site

http://www.plaxo.com/api/openid_recipe notes about implementing OpenID

Brad's Thoughts on the Social Graph

http://bradfitz.com/social-graph-problem/ FOAF