Other info:
StumbleUpon is an Internet community that allows its users to discover and rate Web pages, photos, and videos. It is a personalized recommendation engine which uses peer and social-networking principles. Web pages are presented when the user clicks the "Stumble!" button on the browser's toolbar. StumbleUpon chooses which Web page to display based on the user's ratings of previous pages, ratings by his/her friends, and by the ratings of users with similar interests.
Key features:
Interest groups which are community forums for specific topics.
StumbleVideo which allows users without a toolbar to "stumble" through all the videos that toolbar users have submitted and rate them.
StumbleThru service, allowing users of the toolbar to stumble within sites such.
