So, this is my less-than-perfect attempt at a doradango. (polished mud ball) I read about these about a year or so back, and I've been trying to make a good one since. It's a sphere made entirely of fine dirt particles and water, and the goal is to get it as perfect and shiny as possible. Who says you're ever too old to play in the dirt?! XD
This about the third time I've tried one, and although I didn't get a high polish on it, at least it didn't crack! Here's a few websites with more information on what hikaru dorodango are, and photos of what a finished dorodango is supposed to look like. Mine doesn't come close, I'm afraid. With a well-made one, you could swear you were looking at a glass ball, there's no way to tell it was made from only dirt!
There are also some instructions on these sites to make your own, it's a surprisingly fun and satisfying activity. [link][link]
I believe the people on the show Mythbusters made dorodango once, only, they used something other than dirt... o.O