"In the spring of 2003, Dan Fink got a hamster named Skippy to power a nightlight. It took some imagination. First, Skippy had to be no ordinary hamster, but one of the Syrian variety, a breed that runs particularly fast and goes all night. Next, for all his relative speed, it turned out Skippy could only chug along at 60 revolutions per minute, too slow to charge a battery or generate a volt, so Fink had to build him an alternator out of extremely strong magnets. And then there was Skippy's noisy exercise wheel, which was not only obnoxious, but a waste of energy. Fink solved that by retrofitting it with a smooth ball-bearing."
"Can 'Hamster Power' Help Save the West's Landscapes"
Source: High Country News, 06/18/2009