Why huge amounts of energy generated during various human activities are just wasted?
The discussions in the Product Ideas contest about "Fitness as a Renewable Energy Source" inspired new ideas. I believe this topic could be explored wider, expecially now when the price of energt resouces is so high.
What if we try to utilize all this energy wasted? Let's imagine various inimaginable ways of utilizing wasted energy that was generated in the process of various human activities.