Via Tumblr's reigning science guru Joe Hanson comes a biology video made to go viral: audio of an early-1990s hip hop track stimulates synchronized pulsing chromatophores (pigmented cells) in a squid fin. It's amazing. The video was created by Backyard Brains, two guys who hook up electrodes to cockroach parts to reveal the wonders of neuroscience, working with scientists at the Marine Biological Laboratory in Woods Hole, Massachusetts.
Hansen describes the science in more detail on his site, and the guys at Backyard Brains explain the technology of their setup in a TED Talk below. They've also made it available as a kit called a Spikerbox here.