Remember those Magic Eye "random dot stereogram" things, where if you crossed your eyes just right, you could see 3D pictures?
So. Run the rd-bomb screen saver. Increase the grid size until the seed points are about two inches apart. I like
Now sit about a foot away from the monitor, and cross your eyes slightly so that two of the boxes merge into one, just like you'd do with a random dot stereogram. Now it looks like your monitor is a window and the seething pattern is about ten feet away.
Keep this up for a couple hours and it'll be time for lunch!