Building a simple Hero's Engine from a soda can

Here is a neat little steam engine the Rob Cockerham (of cockeyed.com) made from a soda can. I keep coming across items similar to this over the past few days. For instance, The Purple One linked to a video that includes one (or two?) of them a week or so ago. It's a sort of rube goldberg scenario. Like that car commercial with the rolling tires and such from a few years back... except with gunpowder. Even at about 30 minutes, it's worth a watch.

If only I'd had the internet back when I was an unsupervised kid during the summers. I could've been building steam engines instead of trying to dissolve the limestone gravel patio using muriatic acid (a fool's quest, I assure you), or randomly burning pools of gasoline on the driveway (the asphalt driveway - I find that I lack a certain wisdom at times). In any case, I certainly need to make one of them. SCIENCE IN ACTION, DUDE!