ReadWriteWeb

Our choices for the 10 best Twitter Videos focus on not just number of views, but on videos that help explain how Twitter has changed our culture. From the most popular video about why a group of teenage girls quit Twitter, to an instructional video about how to you use Twitter, to cartoons, to downright Twitterholics, the culture that is Twitter has been explained in many ways.

Another common theme in these videos is introducing non-Twitters users to the Twittosphere. David Lettermen makes great fun of the all too common question, "What is Twitter?" Twitter in HD, featuring Marina Orlova from HotForWords, covers the early days, as well as the creators of Twitter. If you'd like to know more about ReadWriteWeb follow us on Twitter @rww.

Last September, Google launched Sidewiki, a Web annotation service that makes it easy to annotate any page on the Internet. Sidewiki, however, hasn't attracted a lot of users yet and the public discussion about online content continues to happen in comments and on Twitter.

While it's easy to browse comments, finding Twitter mentions of a specific article can be hard. With the Twitter Reactions Chrome extension, however, you can see quickly see what Twitter is saying about a given page without every having to leave the site.