Other music software for Windows includes MediaMonkey, WinAmp, SongBird, and Amarok. I can't speak to whether or not there are Mac versions (I have a PC), nor to whether any of these are any good, especially when it comes to syncing ipods. I've tried the first two of them out briefly as music software and found they were alright in some ways, but missing key itunes features like smart playlists that made them difficult for me to personally envision as itunes replacements (Your mileage may vary). Also, one imported all my playcounts and another only imported *some* of them. One imported my ratings, one didn't have ratings. One did let me make cover art take up as much of the screen as I wanted (Which was pretty cool).
I haven't tried syncing any of them to my ipod yet, because I'm afraid of screwing something up. That'd probably be my last step after bascially making a final decision to go with that software.
Obviously, I take no responsibility for any of this software and anything it might screw up. Use at your own risk, etc.. I'm just mentioning it because I was asked what I've heard of that's out there. Whether it's any good or not is an open question.
I'm testing some of it out occasionally to get used to it in case I have to make a switch. What I really *want* to do, though, is stick with itunes. I just think them to stop changing genres, album names, track numbers, etc. in order to do that. I'm not sure if turning off everything that connects with Apple's servers is a long-term answer (For one thing, they may not allow it in subsequent versions and, for another, I lose key features like genius and CD import track name recognition and so on and so forth)- it's just what I am doing for now.