We just did this from the Atlanta airport this past weekend. It was great. Go to InMotionPictures.com. They also have a service where they will ship it to your home. We may use that this July for a trip to Hawaii as the originating airport doesn't have InMotionPictures yet.
Like I said, it was great. We got the DVD player, 2 batteries, 2 headsets (which worked in the planes jack as well), a battery charger and 3 movies for the 3 days for right at $40. Worked great as the movie screen on our outbound flight was about 20 rows up and we would not have been able to watch the airline's movie if we wanted. It also was nice for DH to be able to watch the movies when he got up earlier than I did and let me sleep in.
Good Luck!