Google reportedly building a secret wireless network
The rumor seems to be confirmed by FCC filings found by wireless engineer Steven Crowley. According to the filings, Google will use up to 50 base stations and 200 "user devices" during the experimental period to create the network. The wireless network will operate in two narrow portions of the 2.5GHz frequency band, which is part of the spectrum owned by Clearwire.
Google tried its best to keep this a secret, even going so far as to redact the request for confidentiality. For now, this is just experimental, and there are no signs that it will grow beyond the testing phase at Mountain View, but this testing is certainly a crucial first step if Google does plan to create its own wireless carrier.