Once upon a time, it was possible to dial a cell phone in cold weather without removing your gloves, provided the gloves weren't too fat and the physical buttons on the phone weren't too small. In this modern age of smartphones dominated by capacitive touchscreens, it takes either bare skin or perhaps a refrigerated sausage in order to activate the virtual controls.
That may change as soon as next summer when the iPhone 5 is expected to arrive. It's entirely possible that the next iPhone (and its iOS companions) will utilize a new touchscreen technology that's being developed by Hitachi Displays. The new touch display can detect both capacitive elements, like fingers, and insulators, like fabric and plastic. That means a gloved finger or even a stylus could be used for input. The new Hitachi sensors are expected to be available in sizes from 3 to 10 inches, so they could be used for iPods, iPhones, and iPads.