Tubesock – Rip Videos from YouTube
http://stinkbot.com/Tubesock/index.html

Ever see a video on YouTube and wish you could take it with you? TubeSock does it.
Just click to download, convert and copy to your iPod. TubeSock grabs YouTube videos from the web and copies them to your video iPod, Mac, or PlayStation Portable. TubeSock knows how to convert the video using the codecs and bitrates best for each device. It can even add the video to iTunes for you. This has been added to World Wide Web Reference Subject Tracer™ Information Blog.