My significant other and I share and iTunes account (don’t tell!), so after I updated my iPad and her iPhone, she started receiving all my iMessages. Whoops! Turns out, though, it’s easy to associate different identities to different devices in iMessages, even if they share the same Apple ID — handy if you share an account with someone, have multiple iDevices of your own and want to set up separate buckets or just want to change the address you send or receive message from (your “Caller ID”). Here’s how.