In this informative money diversity keynote by Bernard Lietaer the author of 'The Future of Money' discusses the need to move past the industrial age monetary concept of a single currency.
Bernard Lietaer opens his keynote by saying that "a political democracy without a monetary democracy is ineffective." More than one currency is required in order to do things effectively. As a world traveler, Lietaer has witnessed how other countries are utilizing different forms of currency to accomplish various tasks. In Belgium there is an experimental currency being used called Torekes. Torekes are earned through various activities that promote urban agricultural projects -- community gardens, cleaning up neighborhoods, etc. -- and can be spent on material that goes towards maintaining an effective agricultural space.
All around the world nations are implementing different forms of currency to support particular projects that individuals are passionate about pursuing. This kind of model is necessary in order for America to not repeat the events of the 1930s.