Buddy Stalker

Kevin Lawver demoed a cool Buddy Stalker mashup yesterday at Mashup Camp 3 that combines AOL's feeds infrastructure, AIM , and Open Authentication to let you stalk your buddies online.  All of it tied together with Rails in about 8 hours (and the last 2 hours were probably just tweaking the CSS).

Personally, I want one more level of abstraction on top of this.  Something like a personal buddy zeitgeist tag cloud, updated dynamically, showing what my buddies are up to.