Handy's or Mobiles
Is it not time for some enterprising company or entrepreneur to create a portal or archway that you walk through that scans for and detects mobile phones.
Ideally this would be all phones, on or off, and it would result in you handing over your phone in an off state into a bag you get 1/2 a tag and the other half is marked with your seat number. The phones are impounded (given to the chief purser or Captain) and returned on the jetway or at the bottom of the stairs when you produce the 1/2 of your tag and show your boarding card stub.
Worst case it would only catch the phones that were on. Those that were off would get on board OK, and the announcements should threaten instant confiscation (with fine) if used before arriving in the terminal building.
When being handed you boarding card you should receive a slip warning of the rules and indicating the fine (suggest something interesting - 1st offence 500 US$ - repeat offence 5000 US$ and blacklisting.
Offences should be reported by the airlines to a Database run by SITA or IATA and paid for partially by the fines.
Interested in comments (especially from SITA & IATA).