I'm Addicted to StumbleUpon

Ack. Thanks to prodding by Josh, I finally made the mistake of installing StumbleUpon in Firefox … and now I’m really seriously addicted to it!  Help… all I can do is sit around clicking the "Stumble!" button all day long. I’ve already found so many cool things that I wouldn’t have known about otherwise. Like this guided visualization for understanding 10 dimensional space (the space of superstring theory)…(my brain hurts…).