Southwest Airlines has embarked on what's set to be the next major step in 21st century air travel, with their recent testing of in-flight Wi-Fi. While only one of their aircrafts is currently equipped with the technology, three more are set to be outfitted as early as next month. Once on board, travelers will be able to use high-tech gadgets like laptops, iPhones, and any other devices equipped with personal Wi-Fi capabilities absolutely free. (Oh, how we love fee-free Southwest!)In addition, Southwest has partnered with Yahoo! to provide travelers with a unique homepage that will provide content relevant to the flights destination, such as weather, shopping, nightlife, and even taxi information. Also included with the Yahoo! service is a flight tracker, which includes a map of the flight path and pictures of some points of interest that you're currently flying over. In keeping with FAA rules and regulations, however, cell phones and VoIP calls will remain (blissfully) prohibited in-flight.