If you already have a 12V adapter auto-type power supply, you need a cheap Empower-adapter for use on those planes that have the Empower ports. You can get one at http://www.magellans.com/cgi-bin/mit...&Args=&Pos=129

Every AA plane I've been on just uses the auto-type ports, but someone mentioned above the Airbus planes use the Empower ports.

Regarding buying a generic 12V adapter at Radio Shack -- beware, it may not have enough power to run your PC. PC's can use alot of watts, and those RS adapters are sometimes pretty puny in their output power. I tried to use one on the road once when my adapter died. It would only put out enough power to either a.) charge the battery when the PC was off, or b.) run the PC when the battery was fully charged, but not a.) and b.) simultaneously. I'd recommend verifying this works in the car, before taking it on your trip.

Eli,
the adapter you have should work, although its somewhat cumbersome. You end up fumbling with two boxes: the 12V-to-AC adapter you bought, and then your normal AC laptop power supply. IMHO it's much better to just get a 12V power supply for your PC.