Robert Langer: To me, the American Dream means that you can do anything you want, anything you dream of.  In particular, one of the wonderful things I think about in terms of the American Dream, is that somebody can be born with nothing, or into adversity, and they can rise up and change the world. It could be create a company, make a great discovery.  I particularly think about people who might have had very minimal education, that they are born poor, and yet that they could dream and actually accomplish, creating companies that are incredible.  You see those things happen.