The Gogo Inflight Internet is an in-flight broadband Internet service offered by Aircell. Gogo allows airline passengers to connect to the Internet through a system of cell towers on land.
Aircell owns and rents a total of 92 towers that cover North America, including Canada and Mexico, and up to 300 miles off-shore in some areas. The towers are cellphone towers that have been outfitted to point their signals at the sky rather than along the ground. The aircraft picks up the signal through a receiver installed on its underside. Once in the aircraft, the data signal is distributed throughout the cabin via a Wi-Fi system. Customers are required to enter their e-mail address and solve a CAPTCHA before using the service.
Official Site: http://www.gogoinflight.com/gogo/splash.do