The iPhone “Jimmy's iPhone” is synced with another iTunes library. Do you want to erase this iPhone and sync with this iTunes library?" Of course , not! I don't wanna erase anything! I just want to transfer one song to my iPhone manually.

I'm reading other people topics, and I really feel angry now. I'm cruising between my house and my recording studio every day , and I need to listen to the mixes I've done in a studio in my car using my iphone , and then at home transfer some new music from my other computer and listen to it on the way to work. Synching iPhone to one iTunes library is the most ridiculous thing that happened to iPhone since iPhone. It actually kills the whole idea of the unit being convenient and simple for all users. Even my old iPod could exchange files between different libraries, as well as serving me as an extra harddrive. But the $500 or whatever phone could not do it ?? This is HUGE disappointment. this actually makes me feel like switching to newest Samsung phone after investing gazillions in Apple. Time to switch for sure.