Electric Sheep is a free, open source screen saver run by thousands of people all over the world, a prime example of which graces the headqurters lobby of Google next to a fullsize replica of SpaceCraftOne.
The braincild of Scott Draves, Elecric Sheep can be installed on any ordinary PC or Mac. When these computers "sleep", the screen saver comes on and the computers communicate with each other by the internet to share the work of creating morphing abstract animations ("sheep" image above). The result is a collective "android dream", an homage to Philip K. Dick's novel Do Androids Dream of Electric Sheep. In Dick's SF novel, the Earth has been ruined. Few animals were able to survive, so robot animals are procured instead.