In their books "Freakonomics" and "SuperFreakonomics," Steven D. Levitt and Stephen J. Dubner explore "the hidden side of everything," with stories about cheating schoolteachers, self-dealing real-estate agents, and crack-selling mama’s boys. The Freakonomics Radio podcast, hosted by Dubner, carries on that tradition with weekly episodes. Prepare to be enlightened, engaged, perhaps enraged, and definitely surprised.