http://www.theaircar.com
The air car hasn't been proven yet - the prototypes have only been able to drive a few miles on an air fill (not the 150 miles they claim).
No pollution? The energy to fill the cyclinders has to come from somewhere. It could be wind or solar or the like, but only when the electrical generators we have now are replaced. But it might be better for air in the cities - move the powerplant outside the city, put scrubbers on the stacks, ship the electricity via wires.
The air car is a good idea. I hope it is developed.
Here are some pictures of the world's first hydrogen filling station - in Reykjavik, Iceland. Picture quality is not great (from camcorder) and I haven't resized them yet (too big, but hey, its free!).
http://66.77.169.171/hydrogen/