I live in a place where they've recently banned the use of mobile phones while driving, with additional penalties for texting. And I have a lot of company: Six U.S. states have prohibited handheld mobile use by drivers, and 20 won't be happy with you if you SMS from behind the wheel.
(It's having an impact. I'm noticing a sharp reduction in "Totally just ran someone over" tweets from friends.)
While the focus is on safety, and rightly so, I do wonder if there might be another benefit: inspiring more people to leave the car at home and take transit. Don't laugh (well, not until you get to the cartoon, at which point I'd kind of appreciate it if you would). A lot of us treat mobile connectivity as a compulsion, and the enforced hour-long severing from the hive mind for twice-a-day commutes is a genuine pain point. And the growing strength of everything from location-aware apps to augmented reality will only sharpen it.
For car drivers, the freedom of the open road, as illusory as it has been for decades, is about to get more so. Mass transit may at times be crowded and uncomfortable, but with the escape to cyberspace just a few keystrokes away, buses and trains may well eclipse the car as the homes of true mobile freedom.
Force me to choose between my mobile phone and my car, and I'll do my best to hang onto the phone. Your mileage, of course, may vary; what choice will you make?