Solar Impulse, a solar-powerde airplane which should fly around the world in 2011, has been tested on the runway. It did not take off, but it taxied around under its own (electric) power.
Contrary to what I believed before that filght will not be made in one stretch, because the cockpit is quite cramped. The flight will probably take a total of three to four weeks due to the relatively low speed of the airplane, and no person could endure that. It is expected that during the cirsumnavigation there will be five landings to swap pilots.
Here is a movie of the first taxi tests: