With nano you have an option in itunes when you connect the ipod "Make ipod disc available" or something similar, I haven't seen that option in ages, I have itouch now. Make sure to tell itunes NOT to synchronise the ipod when it asks, it would wipe it clean. The ipod should be visible as a disc drive, you can browse it with explorer (on Windows), make sure it shows hidden directories. Somewhere in the directory structure distributed over several directories you'll find your audio/video files. They will have cryptic names, but inside there's an information about name, album, artwork, etc. Copy these directories to your PC disc and then import them into your itunes library (best if you store them where itunes keep its files, that way it skips copying them again, if you want that,that is). This will work with your own made audio/video files (I did it twice for my brother's children's ipods), didn't test it with bought files from itunes shop though, I haven't got a single file from them.