Guys, the HD on the PC that I had linked to my iPhone burned down, and I bought an entirely new machine (was due for an upgrade). I wanna upgrade to iOS4, but I think iTunes is gonna try to erase my contacts / pics because it doesn't recognize the PC - is that right? How do I back up my stuff and then get it back after I upgrade, or better yet how do I not erase it to begin with? Also, if I wanna get iPhone 4 or Droid in the future, how do I transfer everything to them?