The concept and implementation were pretty simple. Attach some springs to the bottom of some shoes so you can bounce. (I'll give you one guess who's project this is).
The "springs" are actually snow cone holders from our snow cone making kit (they hold the cone-shaped paper upright to free up your hands). The shoes are hand-me-downs that he wears from time-to-time, but he's just not a dress-me-up kinda kid. Michael started out using different types of tape, but they didn't hold up very well. Liquid Nails (construction adhesive) did the trick.
Once we reached the park and had a suitable audience of other kids and apprecitive moms, Michael donned his Springy Shoes and, sure enough, bounced all over. He actually had pretty good control and did not suffer any mishaps (though a couple of us moms agreed that a crash helmet would probably have been a good idea). He got a pretty good work out before one of the springs loosed itself from shoe.
Then he was off to the next "thing".