[Just another Joe]

But how do you use your cell phone while riding? (without a full face helmet)

If I needed to make a call while riding, I'm gonna pull over. Same thing for receiving a call.
Although, there are bluetooth compatible devices that you can buy that will allow you to make and receive calls while riding.
You probably would need a full face helmet, or at least a full face shield on a 3/4 helmet.

[longtermmemmory]

We need a much better means of using cell phones while riding.

I have seen the police helmets with the big ball sponge shield mic but it is not practical, a full face bug shield defeats the purpose of riding. (and yes I know there are riders out there who are appalled at the notion of riding and talking on the cell but I promise not to call them on my way to my destination)