I did something very simple with Twitter that I quite like.
I took the RSS feed from my ‘friends’ page. Then fed it into the Mac RSS screensaver (which is installed as standard on a Mac). Now whenever my screensaver activates I get a rundown of what my friends are doing. I guess if you have updates on it’s kind of pointless, but I don’t so it’s a nice passive way to get a snapshot of what people are up to.
It looks a little something like this: