A research team at Stanford has developed a thermos-sized refrigeration device that uses no electricity. Instead, it contains some sort of coolant that becomes cold when exposed to heat.
Details on the project are scarce, but we do know that these units would be relatively cheap to produce at around $US50. That makes it ideal for delivering medicines and cold water to developing countries—not to mention a useful tool on a camping trip. [Esquire via CrunchGear]