Scientists from DTU has developed a way to store hydrogen efficiently and safely, thereby bringing hydrogen powered cars closer. There's a Danish press release and the website of their company Amminex. There's even a Slashdot post about it.
Lots of people and companies is working on the problems associated with storing hydrogen in a useful way for cars, and I sincerely hope the Amminex guys are the ones who succed. Just imagine how nice it would be to walk along a road with only hydrogen fueled cars on it. No more carbon-monoxide dizzines and the stench of burned fossil fuels. It would do a lot of good both to people and the environment.