Okay, so I have an iPhone 3GS unlocked on T-Mobile. I do not have a data plan. (If someone asks me why I have an iPhone with no data plan, I am a jobless student who got this phone as a gift, and cannot afford data ) My question is, if I am having a conversation with a friend through iMessage on our iPhones, and then leave my house (no more wifi), will my friend's iPhone know that I am not connected to iMessage anymore and start sending through SMS? Or will I not receive any more messages from any iOS 5 users until I reconnect back to wifi? I really want to use iMessage because I also own an iPad. (If someone asks how I can afford an iPad but not a data plan, this was also a gift ) Thanks in advance!!!