The concept behind these stainless steel Coffee Joulies beans is this: the beans are filled with a phase change material that absorbs heat as it melts—thereby cooling down excessively hot coffee 3x faster. However, the material also releases heat energy as it re-solidifies—which helps to keep your coffee warm for longer periods of time.
In other words, Coffee Joulies help keep your coffee (or any other beverage) temperature regulated through the magic of thermodynamics. The more insulated your cup, the better the process will work.
The project was recently put up on Kickstarter and quickly blew wayyyyy past their funding goal, but you can still pre-order a set of beans if you pledge $40 or more.