Very cool, and it seems like the basics of this technique would work when done by hand, or with layers in a GIMP/Photoshop sort of way.
The aptly named Fantastic maps shows some of the basic steps involved:
|1: Draw Map, 2: Rotate Map, 3: Magic!|
This may be what I need to get me to finish the semi isometric tomb map I have been idly sketching on a post-it for a few months. Then I can get on to trying to kill the players with it.