It has the largest battery capacity of its competitors, with one fully charged K2 able to rejuice a typical cell phone 5 times over; just one hour of wind or sun will give you 30 minutes on the phone. LED lights on the side let you know just how much charge you have left.
You can stand up the K2 or leave it on its side for optimal sun exposure, and a clip in the bottom allows it to hang from your car, bike or ATV an recharge with wind. It comes with a built-in USB port, and a convenient screwcap on the bottom hides all the additional adaptors you need.
The K2 will retail for around $100.