I would like to reproduce the effects of light's finite speeds. So an object that is far away will be rendered as if it were still in a position that it was in previously.
For example, to create a realistic scene in space, the light from some objects will take a few seconds to reach the camera. A given object should therefore appear as it appeared in the scene (fps)*(Z/c) frames ago, where c is the speed of light and Z is the distance from the camera.
Some examples of what I mean:
Visual: VSauce Distortions