I have an iMac that is my main computer. I download all of my music from iTunes on that computer and update my iPhone through that computer. I also have a MacBook that I use while traveling. Is it possible to sync the iPhone to the MacBook and update the MacBook with whatever is on the iPhone (and not update the iPhone with what is on the MacBook)? The MacBook is not updated (iTunes wise) and I don't want to erase what is on my iPhone. However if I could do the reverse of this then that would be better, that way I can download songs to my iPhone as well as my iPod to update for my vehicle. If this isn't possible, is there any way to somehow get what music is on the iPhone to my iPod so I can play it in my vehicle? Thanks.