Thanks for the replies.
If I get this right: can I format my ipod using the windows version of iTunes, go back into OS X, transfer them all over again, and then I will be able to use my ipod with all the music on XP?
I'm a DJ at the campus radio station and I would much prefer to just bring my ipod and trasnfer all my songs on to the computer and play them that way that use CDs.
Then, of course, I would delete them each day before I left.