The
Israeli
Mossad used a cell phone as a weapon a couple of years ago, before the current cycle of violence. They had located a
Hezbollah (I believe) commander responsible for several acts of
terrorism, and they managed to
infiltrate a cell phone to him somehow. When they were fairly sure he had it in his possession, they called it. He answered, and they used a
touch-tone code to
detonate the few ounces of
plastic explosive they'd hidden in the phone casing. There's a
rumor that they spoke with him briefly beforehand, saying something along the lines of 'Hey, listen up, it's us, check this out!'
While this might be a bit over the top, I probably wouldn't be able to resist it myself. Whether the state of Israel should be carrying out assassinations is another matter entirely, one on which I refuse to have an opinion here. ;-)