I have iPhone 4 that I want to sync iTunes library to more than one computer (1 iMac and 1 PC). PC was previously synced with old device. I want to sync iTunes library currently on iPhone and override data on PC. How do I do this? I do NOT want iTunes library currently on PC and override iPhone.
You could however Transfer Purchases from your iPhone to a computer without syncing it, but that is just adding stuff from your iPhone to the computer and is not the same as synching. You can only sync with one computer.