If the iPhone became a must-have gadget, like the iPod did, AT&T's network would have quite a time dealing with all the internet bandwidth being used by iPhones. Fortunately for AT&T, Steve Jobs said in an interview with the Wall Street Journal that the iPhone will use an available WiFi network for internet capability before using AT&T's "Edge". The iPhone is even programmed to use WiFi as a VoIP medium if AT&T service is not available, another innovation in the iPhone.

Steve Jobs and AT&T talked a lot about the iPhone in a Wall Street Journal interview, if you're interested in this kind of stuff, please click here.