Fearing that alot of my favorite clips will be pulled off YouTube soon I have started to archive everything I loved to create some DVD compilations of music and shit. I also got a MP3 player that has MP4 video support.

During this I found a good quick method to download videos in MP4 files off YouTube, basically you need Firefox 3, Greasemonkey addon and this script.

This will add a Download as MP4 link on the right in Youtube. Sometimes it will return incorrect formating that you will need to rename to MP4. It worked for all the videos I got so far.

To watch it on your PC just grab VLC Player.

If you got a MP4 video player, the files usually won't play right off Youtube, you need to usually convert it to MP4 video with AAC audio. MediaCoder is the best open source tool I found for this, as it has presets for converting it for PSP and other MP4 players right off the bat.