We don't have children yet but all of our friends that do keep telling us how many batteries they go through for their kids toys. Currently, we use rechargable batteries for our gadgets, but what about wind powered toys? For $30, a wind powered RC car kit from Japan can run for 3 and a half minutes after sitting in a 5 mph wind for 5 minutes. Cool concept, but we suspect all that waiting around for wind charging will become very old very fast for a young child. If only the run time was longer than the charge time.