I've got a new iPod Touch, do I need a new Apple ID for FaceTime and iMessage
In iOS 6, you can set different IDs for Communications (FaceTime, iMessage, etc) and Stores (iTunes, App Store, iBooks Store). Let’s say one@me.com is your wife’s ID, and your son has already created two@me.com for his own use. The steps would be:


Go to Settings > iTunes and App Stores. Sign in with one@me.com.
Go to Settings > FaceTime and sign in with two@me.com.
Go to Settings > Messages and sign in with two@me.com.


Source: http://www.apple.com/icloud/setup/ios.html