house is green? Think again. Japan's own Nihon Telecommunication System has just revealed a line of windowpanes that actually include integrated photovoltaic cells. The windows are aimed at the (ritzy) residential housing market, and folks that snag a few will reportedly be able to power a PC and recharge their cellphones simply by tapping into the energy generated by these units. Additionally, the glass is designed to shun most of the sunlight from coming into your abode, thereby lowering air conditioning costs and satisfying your needs as an introvert. So, what's the pain for helping out Mother Earth? Around $1,900 per square meter of windowpane -- ouch.