Mobile Phones ARE dangerous when used inflight...

At least if the pilot's using it! [:0]
NTSB Full Story Here
According to a Federal Aviation Administration (FAA) inspector, the pilot was flying above Interstate 81, and communicating via a cell phone, to a friend driving a tractor trailer northbound on Interstate 81... The pilot was maneuvering in the vicinity of the tractor trailer when the airplane struck power lines, and subsequently impacted the ground.
NTSB Full Story Here