Wow, time does really fly. It’s the first birthday of Gogo Inflight Internet, a service that is bringing broadband access to air travelers across the country. Gogo is offered by AirCell, an Itasca, Ill-based company. Anecdotally, many people I know enjoy this convenience and have chosen to fly cross-country on Virgin America just because it has broadband.

Gogo launched last year with American Airlines, and today the airline announced that the service is now available on 100 MD-80 and 15 Boeing 767 planes. AirTran and Delta Air Lines are two other airlines that are providing WiFi-based broadband. In total, nearly 66 percent of all flights between New York (JFK) and San Francisco (SFO) and Los Angeles (LAX) have in-flight broadband.

In addition to answering their emails and surfing the web, folks are tweeting and checking Facebook from 35,000 feet in the sky. Facebook and Twitter claimed spots on Gogo’s list of the top five most accessed sites.

In-Stat, a market research firm, predicts there will be 800 planes with in-flight broadband by the end of 2009 vs. just 25 in 2008, generating $47 million in global revenue. By 2012, In-Stat expects in-flight broadband will be a billion-dollar-a-year business, with demand for in-flight Internet equipment nearly doubling between 2009 and 2013.