Every plane has power. Some used to fly , some used for ovens, lighting, TV, intercom and the like. I flew in a Gypsy Moth once, It had none and you had to wear a leather helmet and turn the prop by hand. AA is not there (yet). The new Eagle. Literally. It will be a real eagle.

My laptop and iPod have batteries in them and work for a while without power.

Seatguru.com will show you who and what seats have power on a lot of airlines, if you mean in seat power for your own personal use.

Note CO does in some widebody planes.