a supernerd at
http://forums.gametrailers.com/showthread.php?t=423337 has already applied the science required to debunk it - "Popcorn pops because the water in it turns to steam and a kernel is about 14% water. So, if we assume a kernel of popcorn weighs 1 gram, it has 0.13 grams of water. Heat that water from 30?C to 100?C would take:
(0.14g)*(100?C-3 to turn the water to steam requires he latent heat of vaporization, which is 2259J/g.
2259J*0.14g= 316J for a total of 316J 41J = 357J.
Wattage = Joules/seconds. If it took about 5 seconds to turn the water in the popcorn kernel to steam, then the wattage required was:
357J/5sec = 71W assuming all power from the cell phone transmitter went into the kernel.
Cell phones typically have 0.75W-1W transmitters in them. With a 1W transmitter, it would take,
334J/1W = 334secs, if all power is transfered to the kernel.
Conclusion: since the corn is popping in 5 seconds... completely fake.
edit - as pointed out, corn kernels weigh about 0.25g and there are 4 phones which could be up to 2W each. Therefore, the energy hitting the corn could be 16 times greater. But the other assumption (that all the power is focussed into the water content of just 1 kernel) is most likely wrong by a factor of 100 or more." - NOBODY PANIC