A company called Squared 5 is offering a program called MPEG Streamclip which allows you to download youyube videos on to your Mac. That's not too exciting, there are several other programs that allow you to download youtube videos. The thing they do that is really cool, is that they then convert the video so that you can play it in almost any format... including a format that will play on your iPod. So, using their software, you can download youtube videos on to your iPod.