This free iTunes plugin allows you to download tracks from your iPod to your iTunes library.
Mac only. I need this exact thing for Windows since the home PC crashed. My music library is only on my iPod for the time being. If you know of something, tell me.
Hey man, you can get at the raw mp3s on the iPod just by hooking it up to the computer and browsing it with Windows Exporer (they're in hidden folders so you have to have View Hidden/System Folders turned on in WE).
This page has a little info on it:
http://www.ipoding.com/modules.php?op=modload&name=News&file=article&sid=829