I can see the new guidelines now:

Cell phone use during flight is prohibited in all cases except during in-flight hijacking


Sorry...this is probably a bit glib. However, all I've been hearing all day is how we can expect "restrictions on our freedoms" in the wake of this cowardly deed. In order to retain something of a sense of humor about life in general, one must attempt to find the silver lining in this. Perhaps the ability to use your own cell phone in flight is such a silver lining....