I’ve never used stumbleupon, but my lord can it send a shitload of traffic around.
Oh yes. StumbleUpon makes Digg feel inadequate.
You know how all of us have nontechnical parents, and they have all nontechnical friends, and we can’t figure out what else they do with their computers except forward us crappy jokes and dumb myths that Snopes disproved in 2001?
Well, they ALL use StumbleUpon.