Here is a link to an article about the first manned fuel cell flight.
It has been in the works for some time, and wonderful to see it coming
to fruition: http://www.gizmag.com/first-manned-f...e-flight/9117/
For those who don't know, Boeing converted a Dimona motorglider to
have an electric motor, and on board proton exchange membrane (PEM)
hydrogen fuel cells (integrated with L-ions) that generate enough
juice to power the aircraft during powered level flight. Neat stuff!

Paul