Having said all that, not using cell/mobile phones in aircraft has more to do with operational issues of mobile networks than aircraft safety. The cell companies asked FAA to ban it to avoid networks going crazy in the early days when so many flights with people using cell phones that could ‘see’ dozens – may be even a hundred+, cell sites at the same time.

Personally I get a little irked at how people including aircrew treat this as if the plane will fall out of the air or something. I obey mostly because of the law and its a good thing to stop people chatting on mobiles due to the nuisance value.

But there is no reason whatsoever to stop people from using mobiles when the plane is still on ground, until take off on immediately upon landing.