I've got a few already, here they are... I'll get started on a few more.

the ones of the face are me, i used photoshop 6 to make a photo of me symetrical, then i lowered the brightness, increased the contrast. and for the white one i just inverted the colors, the matrix one, i made a slightly opaque layer mask over the white areas of the face and put a picture of code behind it, you can barely tell when it is shrunken like that. the "woot!" one was actually a photo of refrigerator magnets on my fridge, the only problem was i only had one set of letters and no punctuation, so it was actually a photo of them spelling "wo t1" which i edited with photoshop. the max one and the deagle one were actually not mine, just in my folder, didn't mean to submit them, the skull one was an interesting one... i was testing some vb libraries for making media players, and one of the visualization settings looked alot like bloody, rusty, smoldering steel. so i took a shot of that whilst "By Myself" by Linkin Park was playing on it and put an alpha map of the quake 3 arena skull over it, painting over the fangs, of course.