I downloaded public data from Hipparcos, a satellite launched by the European Space Agency in 1989 that accurately measured over a hundred thousand stars.
The data I downloaded contains position, parallax, magnitude, and color information, among other things.
Sean Bonner, upon whose blog I discovered this, says, "I highly recommend fullscreen and the use of headphones. Listening to this is hypnotic. I want it to play constantly in the background of my life."