Tutorial Needed: Fading Grid Top Right to Bottom Left


I’m not sure if the title of this post can describe what I’m talking about. I’ve seen a tutorial/movie of this action before, but I can’t locate it again. I’m not sure what you would call it. An example of this action is on the http://www.joshuabell.com website. When you transition pages, there is a grid over the picture on the left that slowly disappears. How is this done? And, could you point me to a link/movie clip that could help me out?