How do I use my computer to back up my iphone and my girlfriends iphone and ipad?

I would like for us to be able to share app's but still keep separate itunes accounts.

You can't share apps. The easiest way would be for her to have a separate user account. iTunes makes you authorize iTunes so you can't sync them all with separate iTunes accounts.

When I plugged in her iphone into my computer all her apps migrated into my itunes account but some things like her ibooks moved to my phone but did not stay on hers.

My wife and I share a single iTunes account for our two iPads, two iPhones, an iPod Touch and an iPod "Classic".

Apps share across all devices without any issue, as do music and videos.

Email, contacts and calendars are synced to separate accounts, so she has hers and I have mine.

The only issue I haven't figured out is photos. I haven't been able to figure out how to have iCloud sync PhotoStream to our devices so that they have the same pictures. I can sync the photos themselves using Aperture and then sync back to the iOS devices, which works, but would prefer having a unified account for PhotoStream while maintaining separate email, contact and calendar accounts.

Otherwise, this is a no-brainer and it works great - we buy apps one time and have them synced to all of our devices.

Skubalon,

I don't follow. You said you guys share aiTunes account but then you said you have separate accounts for contact, email, etc...

How do you do that?

We have one account that is our iTunes store account. All devices use this account for managing all purchases through the iTunes store.

Mail, contacts and calendar are different accounts. Under settings, simply set up an email account with whatever account you want (me.com, exchange, gmail, whatever).

iOS treats store accounts separately from email, contacts and calendars.

Does that make sense?

Yes. Thanks.

That I knew you could do but the OP said he wanted to maintain separate iTunes accounts.

I did but at this point I'm just ready to make it work.

You can try to authorize all the accounts in your iTunes. I've never tried what you are doing. I think you will get the best results out of things to either have separate windows accounts and sync separately, or by starting over on one of the devices and having the se iTunes account on all devices.

The best way to share apps is to have the same iTunes account (note you may lose some things purchased under a different account).

Are they on ios5? If so back up to the cloud. It's easier. Also if you set them all up on the same iTunes account you can download any downloaded app free from the app store.

We use the same iTunes account. I have aps across 6 devices (between me, the rib, and offspring).

I think where op may be confused is hen talking about syncing email. Don't let iTunes sinc email. You can turn that off in iTunes when you hook up each device.

Instead set up email on the device using settings/email. You will need to know your email settings to do this. It will pull email, but then leave it on your server do that you can download to your computer like you normally would.

Gigemhilo do you have one universal iTunes account? That's what we are discussing. The OP wants to back them all up to the same iTunes and share apps with separate accounts. Now the op is considering going to one iTunes account and that is the discussion.

Yes, we have one iTunes account. when my wife or the kids want something, they tell me and i buy it. its especially good for the kids because they would buy everything if it were up to them. plus i know what they are putting on their ipods.

my commentary about email was to when op asked about "what about email, contacts, etc.". i guess i read into that wrong. my bad.

[This message has been edited by gigemhilo (edited 12/28/2011 10:38a).]

[This message has been edited by gigemhilo (edited 12/28/2011 10:38a).]

[This message has been edited by gigemhilo (edited 12/28/2011 10:39a).]

I like that for Kids. I'll have to keep that in mind.

Unless I'm mistaken, Photostream and iCloud sharing only works through the same iCloud account, which does not have to be your iTunes account. I think you can set up a separate iCloud account and use that on each device so that photos stream to everyone's device. That would also let everyone share the same iCloud calendar, which could be very useful for families with multiple iOS devices.