A mere couple of years ago I rode a bus line that was strict on No Cell Phone Use. Nobody died or successfully sued, that I know of; as for me, I managed to get all my masters-degree reading done and go to bed at a decent hour.
Speaking of. If any a'yous are ever in NYC, check out the Ear Inn on Spring Street waaaaay the heck west near Greenwich St.--one of the oldest bars in the city with a "No Cell Phones" rule enthusiastically enforced (with a brogue, if you're there at the right time). Saliently, un-enforced go the "no drinks outside" rule, as well as the unwritten "dumpy-looking places are terrible" rule.
So far we're lucky that the NYC subway system is, by nature of being buried beneath asphalt, a phone-free zone; a recent trip to Chicago showed me just what we're in for if Bloomberg has his way and service is brought to the subway tunnels.
I pledge that my first act as multi-millionaire will be to fund the installation of Faraday cages around theaters. And whatever else I can afford, muahahaha