So i currently use a pc, but i have a sperate internal HDD with all my itunes pruchased music, and all my other music i, have, come by................. and my itunes movies/tvshows (cant find my iphone apps on the disk...) but anyway, my question is this: im planning on moving to OSX soon so, ive waited so long for a reason, and now i think im ready, given i have the money now. i think i wanna do an imac, and a 17inch macbook pro. but what worries me about two systems is that i want my music and vids always up to date on both systems so there are no discrepincies. do i make duplicates on my non itunes files? and then just "authorize" one of my macs and transfer my purchases? im sure this is confusing... what do you guys do? what do you suggest? i wanna be able to buy a song on my imac, and then also have it on my MBP when i take it to school or something. and no, i dont think an external HDD is the answer. thanks!