The cell phone is a marvelous invention, but you should not use it while driving. If you're looking at a keypad and punching in numbers on a cell phone, vehicle navigation system, radio etc., it’s impossible to focus on what’s ahead of you at the same time. Driving is a full time job. It takes 100% of your concentration, and talking on your cell phone while driving can take up a large percentage of that concentration. Not being focused while driving can easily lead to a collision.