Ken Murphy built a time-lapse camera and installed it on the roof of the Exploratorium museum in San Francisco. The camera captured an image of the sky every 10 seconds for a year. From these images, he created a mosaic of time-lapse movies, each showing a single day. The days are arranged in chronological order.
He used a Canon A520 point-and-shoot digital camera controlled by a Soekris net4801 computer running Ubuntu Linux and the gPhoto open-source image capture application. (more info)
A History of the Sky from Ken Murphy on Vimeo.