Also, a lot of touch screen phones (iPhone in particular) have been adapted for modern use. With my Klipsch Image S4i headphones (or with the natural iPhone 4 headphones), you can answer/hang up calls using the headphone controls. I've yet to figure out whether I can activate voice control for dialing, but that'd be even better.
When I need to dial on my iPhone in the winter, thin cabretta leather (damascus d302 for example) works wonders, at the same time keeping your hands dexterous and warm. I feel a lot of the problems you're describing are more functions of outdated technology, than poor design in general.