Wow. I didn't vote in this challenge and completely forgot to go back and look at the results. This is way cool. This is the kind of thing I see and want to shoot. Love the rebar and the rust.
Oooh. Harsh angle, harsh lighting. Very effective. Like skewsme said, you might try playing with contrast and see what happens, but this is good as is.
I thought this was a great wall shot. It has a really harsh and desolate feel to it - perfect. This is the kind of photo where I'd probably play with curves and levels for a while, then decide to leave it the way it was anyway ;-)