Pokez has an combo on their menu named "13. You don't want it!" I asked the waiter what it was, and he said, "you have to order it to find out!" I pictured it being a $8.25 plate of bones, horse hooves, and misshapen pieces of plastic. So I didn't order it.
A recent TED talk describes experiments where monkeys were trained to give tokens to humans in exchange for food. A physical space was created where, when monkeys entered, they were given fake money and different human "vendors" would sell the monkeys different amounts of food for a token.
A provocative talk about choice, though some of the research sounds pretty hand-wavy:
Notes from Cook's Illustrated issue #97 (March and April 2009):