I just installed Konfabulator as I've seen several people, like Scoble, blogging about it. I think I need to dig thru the widget gallery. Of the preinstalled ones, I only like the Battery Level and WiFi Signal widgets. But I really like them - as in like them enough to keep the software installed just for them. I've only played with it for 5 minutes, but already I am not interested in any of the interactive widgits - having a nice partially transparent graphic displaying information at a glance works for me the best.
Esp. after the launch of Halo 2, I'd love to see a Konfabulator widget with the status of my Xbox Live Friends list. Maybe something for the XboxFriends folks?
Speaking of Halo 2, I'm headed home now to do just that...