StumbleUpon’s social browsing application has been such a big success in the past couple years they decided expand. They just launched [StumbleVideo](http://video.stumbleupon.com/) which recommends videos based on what others voted as thumbs up and thumbs down.
Unlike StumbleUpon you don’t need a toolbar to use StumbleVideo, all you have to do is go to their web page and hit the “stumble” button. Based on your interests it will try to show you videos that it thinks you will like. Once you watch a video you can then vote if you like or dislike the video, which then affects how many times others see that video when they hit the Stumble button.
The overall concept of StumbleVideo is great because it lets people watch videos from YouTube, MySpace and Google all in one place. From a business perspective it also gives them new opportunities with advertisers because in the future, they could potentially charge companies for each time their video is watched. At the current moment StumbleUpon has an [advertising program](http://www.stumbleupon.com/ads/) that drives traffic to websites and it seems that it has been working out for them as well as the website owners who advertise with them.