There is software that you can find that will do this sort of thing for you, unfortunately I can't think of any off the top of my head, which really isn't helpful now is it?
But now my helpful post:
I figured out a really long way to do this once when I had the same problem, I'm not sure if the method posted above is easier of even if it works, but here's how I did it.
first make sure you can view hidden files on your computer, then plug in your iPod. If you open My Computer you should see your iPod under "Devices with Removable Storage," double click on it. You should then see a hidden folder named "iPod_Control," double click on that, then double click on the hidden folder "Music." You should now see a whole bunch (50-ish if you have around 600 songs) of folders named "Fxx" where x is numbers. When you upload music to your iPod through iTunes, it renames them into a bunch of numbers, but if you notice it keeps the same ID Tag. Now for the long part, if you copy all the music files onto your computer and then import them into iTunes, you can see it exactly like you used to; artist, album, etc. Now if you go into the "edit options" part in iTunes you can see the file name down at the bottom, then just find the file and re-name it so you know what it is in the future.
I know it'll take a while but it's just an option (I found it easier to go one folder at a time so you don't get overcrowded with a bunch of numeric file names).
also I believe that windows explorer shows you song information so you don't have to upload it into iTunes to see it.
anyway, let me know if this helps of if you need me to clarify anything.
