Roxio Labs

There are now so many video sharing sites that it is impractical to even compare them as a consumer. It's like picking breakfast cereal, you just have to try one and see if you like it. At some point they will be more numerous than cable channels. [Ed: and you will need a remote to "surf" them.] The PC becomes the "Idiot Box 2: Revenge of the video bite."

Lightreading.com has a super cheat sheet which, although not exhaustive, is still impressive.

See it here.