You've probably been getting chain emails from coworkers about a March Madness pool going around the office that could win you $100 or something. But check this out, Warren Buffet recently opened registration for the Quicken Loans Billion Dollar Bracket Challenge. Along with the shot for the billion, the top 20 brackets will win $100,000! Just go to quickenloansbracket.com and fill out the registration form for your chance.