Rip YouTube videos/audio

The tools you need are described on blog.joff3.com. One thing I noticed: the ffmpeg command there re-encodes the audio which might loose some quality. To just dump the audio off the Flash video, use:

ffmpeg -i somevideo.flv -acodec copy output.mp3

This will just extract the audio track without doing anything to it.

You could also try vixy.net.