Interesting looking Kickstarter project for something called Coffee Joulies
Coffee Joulies work with your coffee to achieve two goals. First, they absorb extra thermal energy in your coffee when it’s served too hot, cooling it down to a drinkable temperature three times faster than normal. Next, they release that stored energy back into your coffee keeping it in the right temperature range twice as long.
At $40 for a set of 5 Joulies, it's a bit too much for the amount of coffee I drink. But a coffee shop ordering a box of 20 sets of 5 Coffee Joulies for $500 would be a great way to set your shop apart from the competition. The hipsters would love it!