The lack of reliable electricity in developing countries puts a damper on more than just technology use -- having to run kerosene lamps, or even those based on solar power, often involves recurring costs that whittle away at very modest incomes. GravityLight has built an LED lamp that just might lift the burden. As the name implies, a weight (usually the very bag that the lamp ships in) generates electricity through natural force: the few seconds it takes to lift the weight can generate 30 minutes of light without ever replacing a battery or fuel supply. The simple construction also has helpful side benefits, such as powering up other devices and a clip that can replace the bag with most anything that weighs around 20 pounds. The crowdfunded project's donation tiers ask $25 to donate a light to the developing world or $50 to also get one for yourself, but it's a small price to pay in the long run -- and when mass production should see prices fall below $5, the GravityLight might just change the lighting landscape for those who need it most.