IPOD start on windows, how to add songs from MAC

My friend has a 40GB IPOD with PC, he has already loaded 250 songs on his IPOD, he wants to loan me his IPOD so I can add my library from my MAC. How can I do this? Once I do how does he add more from his computer without losing anything which I added? Can someone please e-mail me privately the anser??

Thank you,

You have to combine all the songs onto one computer and then load them to the iPod. I believe the record companies would describe what you want to do as illegal.
One computer will sync with many iPods, but one iPod will sync with only one computer. This is to prevent people from doing what your friend wants you to do (which Onhwy61 correctly describes as illegal), but still allow you to buy iPods for your whole family and download music to them all from your home computer.