After figuring out how to use the iPhone 4's FaceTime feature over 3G, the obvious question was how much data does it use? According to a brief test by 9to5Mac, about three megabytes a minute.
Looks like crap, apparently. Okay, we'll admit that FaceTime is cooler than we thought, but having it only work on Wi-Fi makes it less useful. But after seeing FaceTime fail over 3G, we'll take less useless over being unusable.