I took a red-eye flight from LA to Orlando last night on Song on a Boeing 757. Although I'd flown them before, this was the first time they had their long-promised TV system installed in the seats. The channel selection is pretty good and provided by the Dish Network, but there's more to than just television.
The screens are touch sensitive allowing you to choose from regular stations, pay-per-view movies, a GPS map of your flight, or my favorite "Music Trivia." Music trivia is set up exactly like the trivia games that are so popular at bars. A question appears and immediately the score for the correct answer starts to drop 50 points at a time. After each question, it shows the rankings of all players logged in, their name, and what seat they are sitting in.
They had to reboot the system real quick right before takeoff and we were able to see the system booting in our individual screens. The system is running entirely on Red Hat Linux.