The Stonehenge Robot isn’t the most practical means to keep time, but it’s got charm to spare. Programmed to carefully move any of 14 double-sided cards to display the proper time, Stonehenge gets some leeway as the cards are designed to stick to the magnetic table. The only potential problem is that the robot may require more than 1 minute to shuffle the display. But in such cases, Stonehenge predicts its lag and compensates by simply grabbing the next appropriate digit(s). Here’s a clip of the Stonehenge doing its thing:

[NorrisLabs via SlipperyBrick]