Just over a month ago, American Airlines said it was installing Wi-Fi to its entire domestic fleet. Now, they’re going to allow streaming video to be played on Wi-Fi-enabled personal devices such as smartphones and tablets. While many airlines offer television channels and a selection of movies to be played on screens on the cabin ceiling or on the back of chairs, this new service will offer a wider variety of movies that travelers will be able to play on their own devices. No word yet on the cost, but it will likely be in line and in addition to the $8-$13 they charge currently for Wi-Fi. “By expanding…