I recently installed Flotzam on my new laptop and it's really really cool. I've got it running as a screensaver
From the Flotzam site:
Watch the flotsam and jetsam of data that you care about in this mash-up of Facebook, Flickr, Twitter and blogs. Using this simple application, you can configure what you want to watch and the speed in which you see it. Want to view what your Twitter friends are doing? Want to see the photos your friends have posted on Facebook? Or maybe their photos on Flickr, too? Download now and have all of your photos, Tweets, Facebook invites & pokes and feeds come to you!
What people are saying about Flotzam:
"Flotzam is controlled information overload."
"Flotzam takes the ADD Twitter generation to a new level of channel surfing."
"Flotzam is the digital panopticon."