More and more airlines are offering Wi-Fi on their flights. Of course, there’s usually a charge for it. And why wouldn’t there be? Airlines are charging for everything now—food and beverages, blankets, window seats, carry-on luggage. The Irish airline Ryanair even plans to charge passengers to use the restrooms. I guess some remodeling will be in order because right now, the locks on those doors are no match for what a couple of pints of Guinness will do to someone’s bladder. As airlines continue to nickel and dime passengers to death, at least some of them recognize that offering something for free once in a while will go a long way to keeping travelers happy. And I’m willing to bet that most people would prefer free Internet access for the duration of a flight over a free blanket. To that end, AirTran has partnered with T-Mobile to offer free Wi-Fi on all flights for a limited time. Starting May 10, Wi-Fi will be available to passengers for free on all AirTran flights. The free Wi-Fi campaign is sponsored by T-Mobile, but the actual network access is provided by Gogo Inflight Internet. Travelers must register for a Gogo account before embarking on their trips. The free offer ends May 23, 2010, but the Gogo account will allow passengers to purchase Wi-Fi sessions on subsequent flights after that date. The access will work for both laptops and handheld, Wi-Fi capable devices, although there are some prerequisite specs and specific supported devices. AirTran isn’t the first airline to market a period of free Wi-Fi on their flights, but it is the first one to provide a free inflight phone to go with it. During the same time period, people flying on AirTran from Atlanta to either Baltimore or Boston have the opportunity to test drive the HTC HD2 smartphone, which launched just over a month ago. The phone can be checked out in the Atlanta airport, and then surrendered upon arrival in Baltimore or Boston. If you’re traveling on AirTran between those dates, be sure to take advantage of this offer. And if you’re not, maybe now is the time to plan a quick trip.