Energy is all around us every day. The tricky part is harnessing all that energy to be put to more useful tasks. For example, walking around uses energy, energy that we're just letting go. But Dr. Cedrick Ngalande doesn't like that, so he's developed the Green Erg generator.
"This is basically a dynamo which is being driven as a result of friction between the ground and the blocks. The small yellowish blocks (these are covered by rubber in the real commercial product) rotate as you pull it. They are designed to rotate even on bumpy run even roads. We have tested it on moist lawns and have worked. It is very smooth so much that you basically don't feel any disturbance as you move along.The generator is aimed at Africa, where electricity can be harder to come by.
At normal walking speeds we have gotten more than 2 watts which is more than enough for running cell phones or radios. I envision that people will attach this to themselves and walk with it - or even attach it to an ox-cart, a skating board, bike, etc