The Devotec Fuel Micro Charger is the world’s smallest phone charger. It’s a 220 milliAmp hour battery that’s only half an inch thick, 1.3 inches long and 0.9 of an inch wide. That means it’s small enough to hook on a key ring and carry around in your pocket without even noticing its presence. Fuel carries enough juice to give you around 20-30 minutes of extra talk time. Look upon it as an emergency backup until you get to a place where you can fully charge your mobile phone. Fuel itself is rechargeable and can hold its charge for at least a month. In fact, it won’t need to be charged for as long as three months if you don’t use it. If you do want to use it, just plug it into your phone and it’ll start charging.