Just when you thought you'd seen eveything the web had to offer.
StumbleUpon is a internet browsing tool. You sign up, download the tool bar and select topics you’re interested in. Then, as you surf the web, hit the “I like it” icon in the tool bar to share sites you like. When you need a diversion, hit one of the channel icons (websites, pictures, videos, friend’s favorite stumbles) and you will be taken to a new websites that corresponds with your interests.
I’ve been Stumbling for about an hour now and I don’t think I’ll be getting any sleep tonight.
