Not sure, but I read the iPhone is sort of unique in that you cannot can't turn off the radio completely? This was from some article about wifi on a plane, so maybe what I am remembering is wrong and that you can't turn on wifi without the cell being on, too. I have use my old Treo (don't have anymore) on AA in "flight mode" and nobody said anything. I did have AA ask me about a small Creative Zen Nano (just an mp3 player) and they made a bigger deal than I thought they would only because it had an FM radio receiver. This was during the part of a flight where you were allowed to use electronics, too. I guess it depends on the flight.