Motion blur is one way photogrpahers depict fast action in a picture. This is usually achieved either by using a slow shutter speed and allowing the subject motion to blur or by panning the camera and allowing the background to blur.
Digitally mimicking this photographic blur is computationally complex but essential if game and movie animators want to create convincing video footage. Researchers from the Computer Graphics Group at MIT’s Computer Science and Artificial Intelligence Laboratory have pioneered new techniques for computing blur much more efficiently, in a matter of minutes rather than the hours it currently takes to render.
Read more about this new technique at: MIT.