[Video Link]. How does this work? The YouTube comments point to the basic idea being that the sodium in the soy sauce causes the legs to move, even though the squid is dead, by some definition of death, anyway... From the YouTube description:
There's still some question as to whether or not it's officially "dead" at the time of serving. The brain is probably still in the body, but a significant part of its nervous system, the giant axon, I believe extends into the mantle, which has been cut. I'm not an expert on squids so I can't really come to a definite conclusion about that.
As you can see in the beginning, it's not moving at all when it's brought out so I assume that signals around the body have stopped, whereas a fresh intact squid out of water would constantly move around. This doesn't necessarily mean that it's "dead" but it seems to me that it's at least incapacitated.
Paging Boing Boing science editor Maggie Koerth-Baker to the comments, please!Over at G+, Dustin Hoffman described it as "a culinary seizure."
(thanks, Miles O'Brien)