"Pixelated" effect?

Does anyone know of any tutorials on achieving an effect like this:

http://www.ravijour.com/

The effect i’m looking for is the initial transition after the loading completes - taking an image and performing what looks like an enlargement of each pixel, then tweening it back down to normal size. I’ve seen it used fairly extensively but can’t quite figure out how to do it. I had thought it might be acheived through using the transition manager, but the “pixel dissolve” effect isn’t really what I’m looking for.

Any help / ideas would be appreciated.