The 'Eco Sign' was designed by Cheolyeon Jo and Youngsun Lee and has to be one of the most efficient inventions of all time. The only minor hiccup is that you will probably get run over by a car while trying to find out where you are going.
The 'Eco Sign' is an electronic manhole cover that gives directions to bus stop or train stop. Did I mention is was powered by rain drops that spin in an electric fan underneath? Pretty neat stuff, as long as you don't spend too much time standing in the middle of the street. Check out more on the 'Eco Sign' below.