It's actually a ram-air kite. The only manufacturer that I know off-hand is Big Air Kites (A company related to Big Air Sportz, makers of skydiving mains).
You probably noticed that the woman in the commercial was also towing a sled. The kites have enough power to lift somebody off of the ground in a strong wind, so they would probably work well enough to pull a skier and her cargo. It would certainly save a lot of energy while crossing big flat stretches of land.
By the way, para-ski is an entirely different sport.
(This post was edited by indyz on Feb 7, 2003, 10:57 PM)
I know folks have used various means of getting up-hill, also. Like rounds -- I think there was actually some film of it in one of Warren Millers' movies. Basically a reversed type harness, they just cut away at the top of the hill