Sorry to drag this topic back from the nether, people, but us Europeans have only just been blessed with such a photoshop-contest-worthy film as Sin City, and I can't really let the opportunity go to waste.
Anyway, for Angst who posted up this picture:
I've done my best with it, but it doesn't really seem the perfect Sin City material, as nothing in the original really stands out as being colour-worthy. Pretty happy with how the stairs came out though, here you go:
I'd also like to call everyone's attention to my own avatar, a self-portrait that was auto-SinCityised the moment I took it by the technological wonders of the GameBoy Camera. I'm thinking of adding a splash of colour to it, but I can't really figure out how I should go about doing it. Anyway, here's what I'm talking about, if it's changed by the time you're reading this: