Jakehall - the effect is called the Pulfrich effect. You can find out a little more about it here:http://www.rainbowsymphony.com/3dpulfrich.html
and there's a little demo here:http://dogfeathers.com/java/pulfrich.html
Several specials have been broadcast using this effect, and they usually tell you where to pick up free glasses. The first, I believe, was a Coke commercial during a Superbowl about 10 years ago. One of the more recent was Sharks on the Discovery Channel (well, if they don't do HD, maybe they can do 3D). :-)
Do a Google search on Pulfrich and you'll find a lot more on this effect.