Vidz2Podz is a simple, easy to use Windows program that enables you to download movies from these major video sharing sites:
and use them on your desktop. It will automatically convert it into MP4 and save it for you. Vidz2Podz imports the file into iTunes, so that on the next sync it will appear on your iPod Video. Simply enter in the YouTube page URL and Vidz2Podz will download the file, convert it, and then import it directly into iTunes. The next time you plug in your iPod video it will automatically transfer. If you don't have an iPod video, you can still watch the movie in iTunes.