BUILD IN A BREATHALYZER AND YOU'RE ON TO SOMETHING...:

Thumbs on the Wheel
By MARK A. SHIFFRIN and AVI SILBERSCHATZ, 10/05/09, NY Times)

[T]he way to stop people from using cellphones while driving is not to make it a crime. Too many drivers value convenience more than safety and would assume they wouldn’t get caught. A more effective approach is to get telecommunications companies to tweak technology to make it difficult or impossible to text and drive.

When a cellphone is used in a moving car, its signal must be handed off from one cell tower to the next along the route. This process tells the service provider that the phone is in motion. Cellphone towers could be engineered to not transmit while a phone is traveling. After a phone had stopped moving for a certain amount of time — three minutes, maybe — it would be able to transmit again.

Another solution would be to install hardware in cars and software in cellphones that would disable some phone functions when cars are moving. It would be the electronics equivalent of putting a guard on a knife handle or a grill over the blades of a fan.