this involves focusing with a very narrow aperture (in this case, I think, f/16) and then moving the camera during exposure. You can experiment with different kinds of movements to get different effects.
rinac may be the best practitioner of this technique...
So I guess the idea is that since you're dealing with good DOF, you'll get good sharpness all around (i.e. everything is recognizable) and the only blur will come from the slight camera motion. I didn't articulate that well. Guess I'll have to try it. Nice shot by the way...