AW-style Pictures

Hi all :)

I use photographs I've found from various sources to illustrate players and NPCs in my AW game. I've been trying to tweak them to give them that "Apocalypse World"-style look of the illustrations in the rulebook.

Anyone have any idea of the way the images in the rulebook were manipulated to get that effect? Or suggestions of how I could get a similar style? I've been playing around using GIMP (the free photo-editing software); any tips would be greatly appreciated!

Vincent goes over the basic process he used to create the AW images in the replies to his post here:

http://lumpley.com/comment.php?entry=499#3

Awesome, thank you very much!