Two iPhones, one household: Installing iOS 5 without obliterating data I know these three couples. All six people have iPhones, and they have all recently asked me about syncing. I told them to wait until iCloud came out so I could give them a more informed answer.

I know that once you have iOS 5 on your phones, you can have separate iCloud accounts while sharing an iTunes Store account between you. That is not my question.

But to get iOS 5 on your phone, you have to plug it in and sync it with iTunes one last time. I can't test this, but I'm assuming that unless you create separate Windows or OS X accounts for that one lousy sync, you can't do it without screwing up at least one person's data.

That is my question: Is there a good way to install iOS 5 on two iPhones, from one computer account, without causing the data apocalypse you're trying to avoid by upgrading to iOS 5 in the first place?

EDIT: It occurs to me that after I plug in the phone, I could just uncheck every single "Sync" option underneath the tabs on the device screen in iTunes. Is that all it would take to upgrade to iOS 5 but leave the device untouched?
You don't mention if they're on the same computer. I am in a similar situation, two iPhones on one iTunes account, except we each sync to a different computer. I expect (based on the note above) to be able to upgrade both two iOS 5 and use two different iCloud accounts. As our data currently lives separately on two computers (Snow Leopard), I'm optimistic that we won't clobber one another. Perhaps this is an option for your friends?