light painting - achieved using a slow shutter speed and flashlights. I am so going to try this sometime!
The beauty of slow shutter speeds and a tripod.
By Dennis Calvert - 'Beautiful mind-melting examples of Light Painting'
Painting with Light
Kind of want to do something like this in an old building
Star trails: how to use your camera's Bulb mode to capture stunning long exposures
Painting with light photography
Daytime Long Exposure Photography Tips