Hydrogen is explosive, yes but it is lighter than air and goes up. Gasoline flows downward and spreads. I was talking with a JPL scientist who pointed that out. But true, the enormous pressure required to store enough hydrogen is a big factor limiting the fuel cell vehicle to just a few concept cars - a working but very expensive concept car.

On issue of demand for electric vehicles, rent "Who Killed the Electric Car", a great documentary on the EV-1 that GM leased to people until they got a California law overturned and it was no longer required. A lot of people are stilll up with GM taking them all back and destroying them. The CEO even now attempts killing it was a big mistake. Also check out Tesla Motors. They have sold all of the cars they plan to make, at $100,000 each. Truth, not a *big* market compared to the Yaris or Precis but my point is, there is demand.