Last spring I did some work with trying new rendering techniques (new to me anyway). You may remember my windmill tests. I am going to be using some renders for my thesis so I went back into mental ray contour rendering workflow and did another test render of some models. Instead of using lights for shadows I used ambient occlusion in mental ray. The great thing about this type of rendering is that its blazingly fast. This full HD render was probably under a minute on my box.