H/t to JB, Medieval Robots' London correspondent, for passing this along. The geniuses at Hublot, the Swiss horological firm, have built a replica of the Antikythera Mechanism as a wristwatch.
The story of the Antikythera Mechanism involves a shipwreck, lost treasure, Archimedes, an emperor's ransom, and cosmological know-how. The device itself, recovered by chance on a sponge-diving trip near Crete, is over two thousand years old and is the oldest analogue computer. You could program in a date and it would predict (accurately) the position of the sun, moon, and five known planets. Read more about it here.