Sometimes living in Northern California makes you forget about the fact that there is even a need for air conditioning in other parts of the country. But then we remember that summer in New Hampshire when it was so hot and humid we couldn't sleep, and the summer in Boston when we went to the movies just to sit in an air-conditioned room for two hours.

We like to think of creative ways to stay cool without the AC, but sometimes it's just plain necessary.

That's why we're thrilled to learn about Greencore's Solar-Powered Air Conditioning (truly an idea whose time had come). Just think, you could actually crank up the AC in the middle of the day and not feel the slightest twinge of guilt.

Using a single 170-watt solar panel, the Greencore can keep a 600 square-foot room nice and chilly.

Read more about it at Treehugger.