Everyone raise their hand if they've heard a phone ringing while on the takeoff run.

There is no doubt that electronics all give off interference. The likelihood that one would involuntarily bring down a plane with a modern cell phone, tablet, or other FCC or CE approved device is probably below 0.05%.

Those that do not want to follow the rules ... will NOT follow the rules. I think the airline is just trying to cover all practical bases by telling everyone to turn that sh*t off.

I can see a problem arising from some punk kid trying out his new "GPS Jammer" (which they DO sell and have been selling for years). But I would think that if someone had one with bad intentions, they would not follow the rules regardless.

I'm more afraid of those lithium-ion batteries catching fire. Lookup videos of laptops spontaneously combusting on Google or YouTube. A fire on an airplane is DEADLY.

Laptop battery fun: http://www.youtube.com/watch?v=ixIOEPnsgbI&NR=1