Some people might be wowing over Avatar and the blue-skinned peeps, but in the world of science fiction, I always dug what lurked underneath a whole lot more. Adding to the skin is tricky -- trying to make a hideous scar, a bald noggin, or a blue tinge look realistic always seemed a lot trickier than revealing what was trapped beneath the surface -- the robotic limbs ripping through torn flesh, or even the illusion of skin that masked some other sort of ugly truth.

So, while others might muse over the distinct details given to James Cameron's blue-skinned avatars, I can't help but stare at the image to the right from the upcoming Bruce Willis movie Surrogates. (Check out the larger version at Arrow in the Head.) My eyes keep following the teeth as they become hidden under the lips, the whites of the eye usually obscured by the eyelid. I imagine my attraction is due to the fact that while we may not all be robots underneath our skin, take away that outer layer and suddenly we look a little alien.

But still, there's something much cooler about revealing a piece of metallic hardware rather than a human's musculature -- whether it's the cold, hard metal of Terminator, or even special sunglasses revealing the aliens in They Live!

What's your favorite inhuman revelation, where the skin hides something unexpected?