Here's a Reuters story about a homemade light that is changing lives in poor areas of the Philippines. The simple technology is really just a bottled liter of water with a few teaspoons of bleach. Sunlight shines through the bottle and lights up people's homes as well as a bright lightbulb. The bleach keeps algae from growing inside the bottle. This technology would be a great way to light a clubhouse or a shed even in San Francisco.