Need a cold soda or beer quick? The Tinchilla will cool any canned drink in a minute or less. Just insert two AA batteries, ice, water, and your favorite beverage to get an ice-cold drink delivered up to 240 times faster than a fridge.
Seem unbelievable? I thought so, but here's how one retailer describes the physics:
The Tinchilla is a simple device which utilizes the scientific principle of thermal conduction. By spinning the can at an optimised speed the metal of the can is rapidly chilled by exposing its surface to the ice cubes and water surrounding it. The spinning can is also given a slight wobble resulting in a whirlpool effect inside. This whirpool allows as much of the drink as possible to be exposed to the now chilled surface of the can thus rapidly transferring the heat from inside to the surrounding water and ice.
Pretty neat for only ~$10. Link via TechEBlog