BoingBoing pal Frank Boosman says:
NPR's All Things Considered had an interview (audio only) recently with journalist Matt Wald, "author of an article questioning the optimistic vision of the so-called "hydrogen economy" published in the May 2004 issue of Scientific American." Wald talks about "wells to wheels," the total efficiency and pollution from source to use of different methods of powering cars. Apparently buying a hybrid (a Prius, presumably) is just as green as a fuel cell would be.