I have an Eton radio that along with regular AAA batteries or a rechargeable battery pack can be powered by a Dynamo hand crank that folds into its body. UK-based Ecotronic took the same technology and put it into a line of electronic toys that don't require batteries to light up or make sound.
The Dynamo technology inside of each toy--there are currently nine products in the line--converts a shake, squeeze, or crank into energy that powers lights and sounds, and other electronic functions. So you never have to buy batteries for the things and if you're kid wants them to power up they're going to have to work for it.
Keeping with the products' greenness, Ecotronic packages the toys in biodegradable containers made from recycled paper.
The toys are available for pre-order from distributor International Playthings. The Eco Rocket in the video sells for $30.