I was a new iPhone user with the iPhone4, so unfortunately I wasn't able to be grandfathered into an unlimited data package from AT&T, I do have the 2GB plan however, and only use half on a really busy month. I really like iMessage when I'm at home, the messaging over Wi-Fi is a lot faster and more reliable then typical SMS, but when I leave the house, iMessage is still active, and uses the 3G network to send messages. I have unlimited text messaging, so when I'm not connected to wi-fi, I'd much rather just use SMS messages. Is there currently a way to have iMessage work only on Wi-Fi? I haven't seen anything, so I highly doubt it, I was just curious if they had mentioned anything about the possibility.