Utter nonsense
For those non-pilots on this website mobile phones do not cause planes to fall out of the sky. They do however interfere with some navigational systems, usually the more modern aircraft.
To say they have never caused an accident is not accurate because the truth is we don't know. There are a lot of unexplained events. I personally have seen navigational systems go crazy and upon a search of the cabin found either a phone or a cd in use. If that had happened at a critical stage or during a particularly stressful approach ( e.g. weather, tech problem ) it might have been enough to cause trouble. ( We do crosscheck with other nav. equipment )
The simplest answer is to turn them off. Surely people can go a few hours without them.