I have a couple of kids lying around the place (not mine) and I was struck by the same old idea that if only you could harness their energy you could power so much. Most people have had the idea to put them on a hamster wheel attached to a dynamo I reckon but you can't really do that.
Then it struck me, the hamster wheels already exist, childrens parks and playgroups. Why not attach dynamos to kids parks? Anything that moves; swings, roundabouts, see-saws...they'll all generate kinetic energy which could be stored in a buried generator and used to power things like street lights (they'd have to be supplemented by the main grid if necessary of course).
The energy of children has been wasted for too long, it's time to put it to use. Who's with me!