The use of electronics in flight is a contentious subject. Well, contentious in that the FAA doesn't want you to do it whereas pretty much everyone else thinks it's probably OK. There is a danger though, according to the New York Times, and it's the FAA's rules.
Sure, keeping your phone on during a flight won't make the plane crash, but it could get you arrested, or even assaulted by other passengers. The New York Times' Nick Bilton lists some examples:
In September, a passenger was arrested in El Paso after refusing to turn off his cellphone as the plane was landing. In October, a man in Chicago was arrested because he used his iPad during takeoff. In November, half a dozen police cars raced across the tarmac at La Guardia Airport in New York, surrounding a plane as if there were a terrorist on board. They arrested a 30-year-old man who had also refused to turn off his phone while on the runway.
Considering these instances which are proof positive that using electronic devices can get you into serious trouble on a flight, and an absence of evidence to suggest that using them can actually put the actual plane in danger, it would seem the rules are more of a hazard than anything they aim to prevent. Of course the FAA is forming a new committee to look at things, but cell phones won't even be considered. But here's to hoping we can take at least one step in the right direction. You can read more about how these rules themselves are the danger over at The New York Times. [The New York Times]