Google recently applied for an experimental license from the FCC to "test up to 50 base stations and 200 user devices [...] Base stations will be indoors and outdoors, with the range of each 100-200 meters, and 500-1000 meters, respectively. Both directional and non-directional antennas will be used. The experiment is to take place within a two-mile radius, so this is a quite dense network, which could have very high capacity for carrying data."
But the really weird thing, is apparently Google has requested that the details of the project be kept secret. And the FCC seems to not mind! Full article here.