At the Tokyo Games Show, it was revealed that Metal Gear Solid developer Hideo Kojima experimented with a custom controller for Metal Gear Solid 4.

"We tried running electric shock waves, install a pulse reader ... we also tried to build a controller that's receptive to the strength of the [player's] grip," he divulged. "We tried a lot, even a transforming controller."

You might be skeptical, but keep in mind they laughed at the idea of a game that you played using a plastic guitar controller. They're not laughing about that one anymore.

(Thanks Joystiq.)