Here is an easy solution:
The cell phone manufacturers know who their distributors are. They should put out an immediate bulletin telling all sales outlets that Middle Easterners are trying to purchase these for use as potential weapon detonators. All customers must be identified and documented and any Middle Easterners who make such purchases are to be reported immediately to the FBI or Homeland Security.
The thing is, that I'm afraid the horse is already out of the barn. It's a good idea for the future but they already have them.
Maybe we should just come up with a list of banned items:
Guns, knives, ice picks, sharp and pointy sticks, rocks over a certain size, heavy movable objects like cars and trucks, cell phones, iPods and all MP3 players, home phones, kitchen timers, laptops or any type of electronics with batteries, electrical light fixtures, any primary liquid that could potentially be used in a binary liquid device (that includes all household cleaning products except dish soap), etc., etc.
That's just a partial list. Would that make you FEEL safer? The reason I ask is because if you stop and think for a moment that doing all that won't actually MAKE you any safer. But if you are into the feel-goodism of the 21st century this would take care of it.