Andy Carol has built an emulator of some elements of the Antikythera Mechanism out of LEGO bricks. A slick video by John Pavlus shows an exploded view of the contraption's operation. Carol's own page explains how to make a gear ratio of 19 when all you have are gears of 1, 3, and 5.
Seems like everyone is on the Antikythera Mechanism bandwagon. Soon, I expect to see an emulator based on a North Korean card section, filmed as part of an OK Go video.