Also known as dorodango.
Mary and I flipped through the channels the other night for 15 minutes, and pretty much nothing was on - except a Myth Busters where they were seeing if you could, in fact, polish poop. They brought in some dude who practiced the art of dorodango.
It turns out you can make a ball of dirty shiny by just applying finer and finer layers of dust (and smoothing it out).
This guy has some very nice pictures of dorodango.
I can't wait for summer, I'm gonna make some shiny balls of dirt!