I was talking about computer graphics yesterday with some of my coworkers, and was reminded of POV-Ray, which they'd never heard of.  I actually used it a little bit back at MSOE as part of a computer graphics course.  It's a 3D graphics program which performs ray tracing.  Ray tracing is an extremely complicated, but very accurate, means to determine lighting and shadows for a 3D image.  It's not used in computer games, because it's not real time, but the results are fantastic.  POV-Ray (which doesn't seem to be actively developed anymore) used to have an annual competition where people could submit their best scenes.  Here is one of my favorites from their Hall of Fame:

It's not an actual photograph, but you'd have a hard time telling the difference wouldn't you?