TubeSock
Perhaps the biggest source of video on the Internet is YouTube. The Apple TV includes no support for either locating YouTube content or playing it. However, for YouTube fans, there is the shareware tool TubeSock, which enables you to save videos from YouTube as Apple TV–compatible MPEG-4 files in your iTunes library. Simply locate the video on YouTube using any web browser, copy the URL of the video’s page, and paste it into TubeSock. TubeSock will give you a preview of the video and you can then click a single button to download and convert the video and place it in your iTunes library.
TubeSock is great for YouTube fans. It enables you to have access to your favorite video clips within Apple TV and it also lets you save them indefinitely. The one caveat is that a number of video files on YouTube don’t start out at particularly high quality, which on the Web may not be all that important because the size of the video clip is relatively small. However, when displayed full screen on either a computer or a TV, you’re likely to see the lack of quality much more clearly in terms of pixilated or blurry images.