I have a bunch of music set up in an itunes library that lives on an external drive at home. I don't really use this to listen to music, it's just my database and what I sync my 60gb ipod to.
I have a second itunes library that lives on my macbook, with significantly less music on it, to save hard drive space.
My girlfriend shares the computer, but is currently working out of town. The problem is that her iphone is synced to the external hard drive library (which is an old beast of an external drive).
I want her iphone to sync to the macbook's library so that she can change up music whenever, as I always have the macbook with me. So how does one change which library an iphone sync's to, and how do you it without losing apps, phone numbers, etc.