When design is used not just to sell more widgets but to solve problems of the world, I am filled with a great deal of optimism. Here for example is the Gravity Light, meant to cleanly, safely and sustainably replace kerosene lamps.
"GravityLight is a revolutionary new approach to storing energy and creating illumination. It takes only 3 seconds to lift the weight which powers GravityLight, creating 30 minutes of light on its descent. For free."