Barack Obama wants all Americans to change their behavior, to make "better" choices about money, health and the use of energy. In his campaign, and now in his White House, he's relied on 29 behavioral scientists to formulate ways of "nudging" us all to accomplish his goals. We talk with one of those advisors and others about how the process works. Does it preserve or limit the opportunity to choose? Is it psychological trickery that smacks of Big Brother or a subtle new form of leadership in a complex and confusing world?