So I found more stuff on this . . .
Wired did an article here:http://www.wired.com/news/culture/0,1284,66356,00.html
It appears these things store wind energy for long periods of time, then releases it over a short period of time to walk:
"The downside is that they might have to wait for days, for the wind hopper to move on and on and then be able to move for maybe five minutes. They are just like snakes. Snakes also lie in the sun for days digesting their food. On the beach the animals have to catch the wind and wait for a long time before they have enough wind in their stomach to go for a walk."
he is also doing a really interesting (time consuming) method of genetic algorithms:
"...he allows the animals to race each other and manually replaces the genetic code (tube lengths) of the winner into the rest of the losers."
Also found this, although I cant figure out what a 'bottle' really is . . .
'"It works with the wings in front, they pump up air in laminate bottles. That you could see as the wind stomach. They eat wind, they put it in the bottles and that's energy which they can use for walking when the wind is gone," Jansen said.'
A google image search of his name
brought up yet more interesting images.