Well we have all been places where the cell phone don’t work. What a pain!. But maybe there are times when people shouldn’t be allowed to use their cell phones, for example, at the movie theatres or during class lectures. NaturalNano, a Rochester, N.Y. based company, is developing high-tech paint that can effectively block out unwanted cell phone signals. Based on nanotechnology, the paint uses particles of copper inserted into “nanotubes”, which are then blended into the paint to deflect radio signals. The company claims that it can filter out unwanted signals, while allowing certain transmissions, such as the emergency notification of surgery for a brain surgeon, to proceed as normal.