“To see this feature in action, use AutoShare to link up your YouTube account to social networks like Twitter and Google Reader. Then, whenever you favorite a video on YouTube, for example, that action will get syndicated out to your network, who will see this shortened edition of the video’s URL.
How To Shorten YouTube Video URL’s
To use youtu.be manually, simply take a URL like http://www.youtube.com/watch?v=FdeioVndUhs and replace the “http://www.youtube.com/watch?v=” with “http://youtu.be/” to get: http://youtu.be/FdeioVndUhs Plug that shorter URL into a browser, and you’ll see it redirects to that video.”
Even with the YouTube URL shortener, the URL’s are still long. However, it will make it easier to conserve space, especially when sharing on sites like Twitter where you only have 140 characters to work with, and every character space counts.