hi i have an iPhone 4 and i noticed the other day that a friend of mine message area on it was blue because he has an older model without facetime. anyway i have other friends with new and older models of iPhones that its not even called imessage or blue? but on my set for my friend it says imessage and blue? anyone know why? i make sure that i tell everyone who has one to mark me as having one too so we can facetime. thatnks!