My personal opinion fwiw is that anyone who can't live without their cellphone for the few hours of a flight really ought to get some kind of a life. Radio phone facilities are available, I believe, on long haul flights so that 'really important' people can conduct their business and lesser mortals, like me, can avail themselves if there is something really important (although I can't imagine what).
When I was a kid I made a 'mobile phone' out of 2 tin cans and a garden-length string. If I shouted and used a longer string we could manage a few gardens range. It seems to me that everyone learned that way because, despite the modern marvels with their internal amplifiers, most people still SHOUT when using them. They are consequently intensely annoying to almost everyone within a garden's (or cabin's) range.
Imagine the scenario if cellphones were allowed:
Aircraft suffers cabin fire ('clever' selfish passenger who knows how to disable smoke detector having a smoke in the toilet perhaps). Fire fed by gallons of Duty Free alcohol in overhead lockers and escalates. Pilots carry out emergency descent and immediate diversion to nearest suitable airport. Unfortunately cabin crew cannot make themselves overheard with emergency instructions to pax because of cacophany of noise from 300+ cellphone users calling loved ones, lawyers, insurance companies etc, and many or all die in the extremely toxic smoke-filled cabin and confusion that ensues.
Just a thought. And as a retired airline pilot, who has been distracted by the noise through the headphones as my own phone (inadvertently left on) called its cavalry charge (or whatever they do), I would prefer that their general use in aircraft remains banned.
Regards
rts