Ice Chess: 2011 - ThinkGeek
This was one of the few cool ideas from one of the Slashdot writers, who is constantly sending us questionably sane ideas. His thought was that you could have a speed-chess game by making the pieces from ice. It doesn't really work that well - as the ice forms, it presses out against the flat base of the mold, so the pieces end up with domed bottoms. Some pieces stand ok, but the wider the base, the worse the dome is, meaning that the king & queen pieces don't stand up very well. We went through a bunch of experimentation to see if some sort of insert could flatten out the bases, but in the end, the potential choking hazard wasn't worth the result.

Ice Speed Chess Set - $9.99