Originally Posted by Somewhere Over the Atlantic
Southwest has a policy of no cell phone usage even in "Game" or "Flight" mode once the doors close.
http://www.southwest.com/travel_center/electronics.html
For a device like the Treo, this raises the paradox of "is it a phone or is it a PDA?" What if, say, you possess this device but aren't subscribing to any wireless services and use it purely as a PDA? Does that mean that it is still a cell phone and is still subject to cell usage policies?
Guidelines for permissible devices: any transmission using personal communications devices (including cell phones in GAME or AIRPLANE mode) is prohibited once the forward-entry door is closed. Flight Attendants will advise Customers when the doors are closed. All devices must be properly stowed while their operation is prohibited.
When indicated by Flight Attendant announcements, during the cruise phase of flight these devices may be operated: DVD, CD, and tape players, personal digital assistants (PDAs or hand-held computers), electronic calculators, hand held electronic games, electronic cameras, Global Positioning Satellite (GPS) receivers, and devices that compose e-mail or text messages without transmitting or receiving.
Actually the wording is somewhat ambiguous. I can interpret this to mean that you cannot sent any transmissions with a cell phone/PDA combination device.