Is it possible to update an iPhone on someone else's computer without losing all your data? I'm getting the phone within the next few days (so long as the provider stops jerking me around) because I can't wait for iOS5, my current phone is on its last legs (a plethora of problems... most annoying of which is that the 4 button doesn't work, which means I can't dial ANY number in toronto since all of our area codes have 4s in them, or send any texts containing the letters G, H or I). If I can just update the firmware on someone else's computer that has iTunes when iOS5 comes out then that'll work fine, I just won't update it until then. I'd imagine that will cause me to lose all my data, though?
What if that other computer is the only computer it ever gets synced to through iTunes, will it make a backup of it for me even if it's used for another phone as well, so I can keep all the settings/data/etc when it updates?