Six sided die with each side made from a gear with a number sitting in the middle. Each gear is attached to an axis inside the die. Recently added diagonal sticks to discourage it from landing on a corner.
Another die made with a gear for each face and the number inside that gear. In this one the gears are attached to each other by intersecting teeth and they cannot move, but it still looks cool if you ask me.
Know someone who's a 20? Keep a little (1.5 cm by 1 cm) photo of them inside this 20 sided die necklace. Comes in two parts. Pass your chord through the hole in the top half, through the loop inside the bottom half, and back out through the hole again. The loop is attached to a platform where you can glue picture.
Four, six, eight, ten, twelve, and twenty sided dice with gears surrounding each number. The gears do not move.
The sizes have been adjusted so that they match each other better than for the individually sold dice. The larger dice have been reduced and the six sided has been increased. These are no longer available in metal due to concerns over wall thickness.
Six sided die with outlines of chess pieces imprinted on the sides. Small, single version of the full color pair (http://www.shapeways.com/model/250768/chess_die__pair_.html?gid=ug) not available in color or steel.