If you don’t have time to watch the movie above, just visit Tooble.tv, download the free Tooble software, cut and paste the URL of your favorite YouTube video and presto, your video is in iTunes. That’s super easy.
If you’re on a PC, or just want more flexibility, also check out the earlier post How to Download Flash Video and Play It Back on Your Mac. (And More.). Contrary to the title, you even get some PC how to instructions there as well.