Mircoformats and portable social network
http://www.glennjones.net/Post/820/Mircoformatsandportablesocialnetwork.htm
"What we need is not only a way to prefill social networking information, but also to dynamically and automatically transfer data between systems."
NetNewsWire + XFN
http://ruk.ca/article/3752
"Because NetNewsWire lacks any mechanism for storing XFN information itself, I crafted an AppleScript-based solution that stores my relationship to each feed's author in a SQLite database."