The Dimona Fuel Cell Plane is the first airplane to take flight powered solely by Hydrogen fuel cells, which is a pretty impressive feat. The plane, which releases no emissions whatsoever, took off on a 20 minute maiden voyage where it traveled at 62 MPH at 3,300 feet. Seeing commercial airplanes travel at ten times that speed and height, it's clearly not going to be showing up at LaGuardia anytime soon, but it's a promising start.
The test craft, modified by Boeing Research and Intelligent Energy, should continue to improve as they work the kinks out of it. Hopefully, eventually, the technology on board will work its way on to commercial aircraft.
Intelligent Energy, via Red Ferret