So, this is really cool: http://sciencetothepowerofart.com
What this guy is doing is essentially using bacteria instead of silver halide crystals to develop photos. He uses a jellyfish protein to make bacteria fluoresce green, or a strain of bacteria that is naturally red. He spreads that bacteria on a plate, and then uses a negative to shield certain areas of the plate from radiation, which protects the bacteria in those regions of the plate. So the bacteria then grow out in a recognizable pattern: Einstein, for example, or an image from the Hubble Space Telescope.