Just read this at Engadgetmobile.com and found it interesting.
There is a company developing a new nano paint called Natural Nano that blocks cell phone signals while still allowing emeregency broadcast frequencies.
The idea would be to paint this in places such as movie theaters so that people can’t make or take phone calls during a movie, annoying the rest of the audiance.
I think it is a good idea. Too bad it has to come to them painting builings instead of people just being considerate and at least turning the phone to silent.
Source: Engadget