There's also a great app called Nocture that can do color/monochromatic inversion, red-shifting, removing shadows, etc. http://www.blacktree.com/ http://www.bl

There's also a great app called Nocture that can do color/monochromatic inversion, red-shifting, removing shadows, etc. http://www.blacktree.com/ http://www.blacktree.com/ Open source: http://code.google.com/p/blacktree-nocturne/ http://code.google.com/p/blacktree-nocturne/ Source: