From the toy description:
The included fueling station is powered by a solar panel and uses electrolysis to safely deconstruct ordinary tap water into hydrogen and oxygen atoms. Simply connect the fueling station's plastic tube to the car and hydrogen gas transfers to the car's patented fuel cell, where platinum plates compress the hydrogen and convert it into electrical energy to power the motors. The car maneuvers like a traditional remote-controlled vehicle...
While the explanation above of how a fuel cell works is somewhat different than my understanding, there is no question -- this is the start of something good. Water and energy from the sun are what ultimately power this toy. No sun? Well...it comes with an AC adapter that will allow you to refill the hydrogen fueling station, but that's cheating if you ask me.
Here are more details on the first remote controlled hydrogen powered toy car.