Electro-Magnetic Fields
Apart from the already mentioned hassles to passengers & crew on-rest, has any aviation authority/airline manufacturer proven that the use of mobiles phones on radio frequency will not interfere with the fly-by-wire signals, Radio Aids & Instrument Landing Systems. With the new generation aircrafts depending on electronic signals from side-sticks/control columns for flight controls, this COULD pose a threat to aviation flight safety unless proven otherwise [announcements made on flights to switch off mobile phones as they could interfere with the electronics on board aircraft is what is the normal practice]. IF allowed, and if different from the one we use on ground, in-flight mobile technology must be ensured safe and proven before getting the green signal from FAA/CAA/JAR etc....