I think General Motors is trying to move their fuel base to hydrogen. The thought behind it is that Hydrogen is the most plentiful element in the on earth and therefore we won't run out or expend it all. They have a conversion process that after using the hydrogen for power, then combines it with oxygen leaving water as the only byproduct of the engine.

Its actually quite interesting to see their "skate board" design since it will work for a variety of different types of vehicles from vans to passenger cars.

They of course are looking to be subsidized by the government now since it aligns with Bush's push for cleaner automobiles.