Lance Armstrong, the world-famous professional cyclist who masterminded and concealed an elaborate doping ring in order to win the Tour de France seven times, reportedly confessed his sins to Oprah Winfrey in an interview scheduled to air tomorrow, and offered to testify against his former friends in the International Cycling Union. The news prompted Jon Stewart to do some soul-searching — like so many others, he purchased and religiously wore one of those yellow rubber bracelets — and recognize Winfrey's mysterious power over fallen celebrities.