I am trying to cut a triangle out of a div and show the background as it is behind the div... I would not have thought this to be possible, but you SO pros continue to surprise me here so I thought it was worth a shot 
This is what I would like to achieve (sorry for the faint image):
Please do not answer this question with a 3 column solution or something similar, I am more than capable of achieving this that way... I simply want to know if there are any cool CSS tricks out there that can achieve this with as a few graphics, if not no graphics, as possible?
This is what I would like to achieve (sorry for the faint image):