Step 1. Open Firefox and follow the DownloadHelper link then click on the "Install the extension !" link
DownloadHelper - Media download Firefox extension
After you restart Firefox, go to Youtube, find a video to watch and click on it. While it is playing, click on the DownloadHelper icon on your Firefox toolbar. This will open a dialog box that will allow you to save the YouTube flash video file to you hard drive.
Step 2. Go to cnet download and download the FLV Player 2.0 Install this player. You can then click on your download .flv files and watch them on your PC. But this still does not put them into your iPod.
Step 3. Click HERE to download the Videora iPod converter. Once downloaded, install the software. You can use Videora to covert your flash files to MPEG4 format that will play on your iPod. Videora can be used to convert the file, then add it to iTunes. Use iTunes to move the files onto your iPod.