Originally Posted by PHL
But, as has been said here many many times - the issue is not so much a flight hazard as it is an FCC violation to operate the cell phones at high altitudes (even 2000' above ground). They jam up more than one tower.
The funny thing about that is there are a couple of headset manufacturers who market an mp3 and cell phone input on their GA headsets. I don't think I want to risk rocking out to Ozzy in front of ATC or yakking away with Grandma Ethel while flying, but it's something to think about.