I'm sure this has been covered before - I have a G5 and an iBook. They are both authorised to to play music purchased on the iTunes store and they both update my account balance etc no problem. BUT if I plug my iPod into my laptop it updates the iTunes on that machine and deletes stuff that is only on the G5 - and vice-versa. I buy songs on both machines so how do I get the iPod to keep the the stuff I sent to it from my G5 when I plug it into my iBook? How can I get the libraries on bot machines to be identical?