full story at :  http://lifehacker.com/5551253/the-u+socket-charges-usb-devices-without-an-adapter

picture comes from : http://lifehacker.com
Nowadays, many of our mobile devices are USB-based, but those darn wall socket adapters are so easy to lose (or not have enough of). Thankfully, this fall, you can plug those USB devices straight into the wall with the $20 U-Socket.