hmmm..... how much?
other thing I was going to try was downgrade to v07 firmware and see if that will make it editable, but, if you will sell lemme know
iMessage is built into messaging itself and all you need is to activate weather with the service provider or add ur email id to work with. As iCrank said it only works between 2 iOS 5 users with email iRAB too so if u wish to check then u must add email id of ur fren(who have iOS5) on ur...