Watch this Nova video documentary about the technology of using hydrogen fuel cell in powering cars. The video is hosted by Robert Krulwich and starring Tom and Ray Magliozzi, the CarTalk brothers who does the weekly Cartalk radio show.
The video is 14 minutes long. The promise of fuel cells is very appealing as it makes cars emit nothing except water as a by product. However, the difficulty is getting enough hydrogen and storing it in the fuel tank. You can learn more about how fuel cells work in this Clickable Car.