Andrew Carol, a software engineer at Apple, has recreated a 2100 year old computer using nothing but Legos. The Antikythera Mechanism was originally built by the Greeks to predict celestial events and eclipses (with surprising accuracy). Carol managed to built the replica in 30 days using 1,500 Lego pieces; including 110 different gears that are combined together to form 8 gear boxes, which each perform a single mathematical calculation.
The Antikythera Mechanism: http://bit.ly/fm4oFK is the oldest known scientific computer, built in Greece at around 100 BCE. Lost for 2000 years, it was recovered from a shipwreck in 1901. But not until a century later was its purpose understood: an astronomical clock that determines the positions of celestial bodies with extraordinary precision. In 2010, we built a fully-functional replica out of Lego. Sponsored by Digital Science: http://www.digital-science.com/ a new division of Macmillan Publishers that provides technology solutions for researchers. Available under a CC-BY-3.0-Unported license.