@Yeah, OK AC
Read the text below the videos and search for the word "hoax". That should clarify things a little.
The entire idea is ludicrous if you consider the maximum amount of power transmitted by each cell phone.
Lets do the math:
Maximum power in GSM is quoted at 2W. The average corn weighs 0.3g.
Assuming that 4 * 2W = 8W is transmitted continously into a single corn, that would raise the temperature of each corn by ~6.3 degrees celcius per second. That would bring the corn from 22 degrees celcius ambient to boiling point of 100 degrees celcius in ~12 seconds.
In the first video, the time from the first phone starts ringing to the first corn pop is 6 seconds.
This calculation doesn't even consider the extra heat needed to actually turn the water into steam.
By the way:
The maximum power transmitted is less than 2W since good antennas for mobile phones are lucky to have en efficiency of 50%, so the maximum transmitted power is then down to 1W or less.
Then there is the time division stuff, which means that the antenna is not transmitting 7/8 of the time (so it turns on for 0.6ms and is then turned off for the next 4ms).
Even with perfect focussing antenna in all 4 phones, you would have to reduce the actual power transmitted to 0.5W.
Then comes the spreading of all that power in all directions as opposed to focussing it at a point ~5cm above the top of the phone as the video would lead us to believe.