1) Works on hardy just fine, but the script and the GUI are broke (thanks to Google) and you have to know how to use ffmpeg and ecasound.
2) Go visit a YouTube video and then do this repeatedly in your command window while the video is downloading into the YT video control:
See that file getting bigger and bigger (byte count) and then it finally stops? That's an FLV file -- it just doesn't have the extension on it.
$ ls -al /tmp/Flash*
3) So, once that stops filling up with bytes, I can then do:
On the above, if it asks to overwrite, say yes except on the ecasound line -- where you might want to change the song name.
$ sudo su
# cp /tmp/Flash* /tmp/movie.flv
# ffmpeg -i /tmp/movie.flv /tmp/monosong.mp3
# ecasound -i /tmp/monosong.mp3 -etf:8 -o /home/yourloginid/yoursong.mp3
And this sticks a file called yoursong.mp3 in my /home/yourloginid directory that is a simulated stereo file.
4) To add a genre, song title, band name, and album info, that's called ID3. There's a handy ID3 editor you get when you install something called "Beep Media Player" (in add/remove programs). You just play the song and then doubleclick the scrolling title of it when it appears. An ID3 dialog will pop open. You fill out the form and click Save. It will save the update even while the song is playing. You can then drag this to your MP3 player's MUSIC folder or whatever and listen to it on your MP3 player.
5) Note that you can also watch YouTube videos on your MP3 player if it has video support. I have one for Rockbox that's posted here. (My son converted his iPod to a Rockbox iPod in order to play videos.)