What do you think about states banning talking on the cell phone while driving?

Washington and California states decided to ban cell phone usage while driving (unless it’s hands free) starting July 1st. I believe there are other states with the same law. But research proves that going hands free doesn’t make it any less of a distraction, since it is the “conversation” that is distracting and not necessarily having both hands on the steering wheel. Would you be for a law that banned cell phone usage completely (hands free included)? I think it would be a good idea, and let’s admit, most of us have driven while talking at the same time. California is predicted to save 300 lives/year by instating the law.