Good point, but you don't necessarily need this input device to be in your pocket, and it doesn't have to come in the form of a phone. For example, here's one solution: accept/decline calls right from your headset without taking the iPad out of the bag. Perhaps the headset will tell you the caller id when you press a certain button so you can choose whether or not to take the call. Dialing can be done through voice as well, or take out the pad and make the call using the touch screen.