Meet the Ballpoint Pen Power Ring from Thanko: a portable device that serves as a writing gadget, a stylus, and a battery for your smartphone. It has a 800 mAh battery to provide your iPhone or Android device with extra battery juice on the go. It can be recharged via USB. The device recharges in about 90 minutes.
The device is portable and easy to use. It is available in two version (MicroUSB and iPhone). You can find it on japantrendshop.com.