However, unlike other signal-blocking technologies which create a Faraday cage, blocking all electromagnetic radiation, this wallpaper only blocks wi-fi frequencies. With this new wallpaper, you can keep your wi-fi signals from leaving your home, while at the same time allowing cell phone and other radio transmssions in.
Your cost, L'Informatcien said, should be about the same as "a traditional mid-range wallpaper." This new wallpaper should be available for sale in 2013.
Naturally, the wallpaper could be used for security reasons, although using wi-fi encryption and disabling SSID broadcast should be enough for most people. In addition, though, it could reduce wi-fi interference in apartment buildings where one may, if one looks at a list of the wi-fi networks around a particular apartment, find a number of networks, competing for the same channels.
It could also be used to block signals in hospitals, theaters and other facilities, although in those cases you would expect that the facility would want to block all wireless signals, including cell phone (although "safety" has often been used as an argument against blocking cell phones in theaters).
There are also people who are concerned about and claim sensitivity to electromagnetic radiation, and this could be used for them, as well, although once again, you would expect these people to want to block all electromagnetic radiation.
Another good thing about the wallpaper: it would, of course, be legal, unlike the attempt of a Philadelphia man to jam cell phones as he was commuting on buses.