Actually, I've been thinking about doing this for a while -- this thread convinced me to put up my MVP to see what happens.

While I'm waiting for DNS to propogate, here's a sneak peek: http://img.skitch.com/20100831-kf41k4mpc4gd612jyhdcbtyxgh.jp...

edit: it's now available at http://dashboard.io -- would love any feedback I can get. :)