
Found this browsing around the M.E.C.C.A. site (Material Exchange Center for Community Arts)(it's the Mungo of Eugene, OR, don't you know) and I'm LOVING it. Kinda makes me want to move back to my homeland...
Mun"go\, n. A word used by sanitation workers to refer to things salvaged from the trash.

My friend gave me this huge box of formula cans and they've just been sitting there kind of mouldering in my tinkering area... I decided today that it's high time I figure out what I was going to do with them, if I wasn't planning on chucking them in the recycling,which I must admit was tempting considering the rabid de-cluttering zest I was seized with today. Luckily I managed to stay those chucking impulses and search Google first, and as per usual my search yielded many fascinating reuse ideas.
This is quite fun and a very fun gift to make with, say, a 9 year old boy who might enjoy bashing the nails into the can.
bearing down a little ramp so that it goes bing, bang, boing, bouncing across the little rubber trampolines. You have to see the little movie of it, you can watch it here.