Didn't Todd Beamer use a GTE airphone in the seatback, not his personal cell phone to make the call? Those are reasonable to have in place for an emergency. They don't receive calls (so no rings) and the calls are expensive enough ($4 to connect, $4 for the first minute) that most people don't use them.
I don't know what phone Todd Beamer used, but the plane was low enough that people got to use their personal phones. Right now, cell towers point down at an angle so nobody gets a signal over 5000 feet or so. A couple companies are working on repeators to allow cell phones to work at any altitude. Some planes have directv receivers already. Having live news and communication with the ground should be considered security. Arming the pilots would be nice, too.