Depends on the ipod, if you have a ipod classic you can use it as an external drive then drag and drop your music folder onto the ipod, then connect to the pc and drag of the ipod into the pc, keep in mind ipod hd is slow so it will take quite some time to copy, i done it once, however if you get your self an external usb drive, you can use that to do the same, just copy the music folder from your mac onto the external drive and then onto the windows pc, big hard drives are so affordable that you should get one anyway and make sure you have a back up of your pc and mac at all times. Good Luck.
I wish to make a tiny correction. All ipods should act like a disk. But ipod HAS to be in the name. Otherwise your hands are tied. You need to take care with iphones, ect to back the tunes up before they go on your device.
You can also make mp3 DVDs. That will be faster. Irongiant was correct as to the slowness of the ipod and USB connections. Putting them on then off will be a killer.
In either case, I believe the tunes need to be DRM free before you move them. I wouldn't know since the first thing I do is remove the DRM. Otherwise I would forget to do that.
