SOLAR WINDOW CHARGER

It doesn't get any more greener than this; anytime your electronic device runs out of juice, just stick this charger onto a window with the sun at full glare and plug in your electronic device. Not only that, it still charges up if no device is plugged in, making it still use-able on cloudy days.

More info here.

So what are your opinions about this device and how would you rate it on a scale of 1 to 10?