"Whoisi is a central site that allows users to add people and their associated web feeds, and then track any number of these people and their feed items using a follower model. Whoisi is a side project by open source evangelist and Mozilla contributor Chris Blizzard. Currently it supports feeds from Flickr, Twitter, LinkedIn, Picasa and any Atom or RSS feed. Once you have added a number of people that you follow, it presents their feed activity in a time-based interface similar to FriendFeed and MugShot, making it easy to track a large number of feeds."
Blogged with the Flock Browser