A pair of origami papers in which the red paper senses how it is being folded and the white paper follows.
When the white paper is flipped over, blintz folding allows the paper to get up, wobble around, and even flip itself over. The microcontroller and circuitry is on the body of the red paper and the white paper is actuated by shape memory alloy.
Project documentation: http://fab.cba.mit.edu/classes/MIT/863.10/people/jie.qi/jieweek14.html
Flickr set: I/O paper