I can't take credit for these awesome stilts... the girls I nanny for are the brains behind the skyscrapers. I give them kudos. Could you possibly have more fun with two tupperware containers and two rubber bands? I think not. This provides lots of fun, while at the same time improves balance and coordination.
If you think these are too high, start small. Margarine containers are pretty low, and offer a wider base. For really young kids, try a sturdy shoe box (which can also be decorated).
Be careful and have fun!