Commercial airliners are about to become the biggest and most expensive iPod accessory yet. Several airlines are going to provide integrated iPod docks for both charging your iPod and for accessing content. Newer airplanes with LCD panels built into the seat backs will be able to display video content from your iPod.
So before you leave, you load up your iPod with a couple of movies you have wanted to watch. Once you are on the plane, you plug your iPod into a dock on your seat arm, and presto, you can watch your own movies on your seat back screen. Pretty cool.