Knock it off, Don Juan. In Spain, the health minister has asked citizens to put a stop to the traditional greeting of kisses on both cheeks, to help prevent the spread of H1N1, or "swine flu." Some schools in the U.S. are asking students to refrain from high fives and officials from France to Lebanon and Kuwait have encouraged people to limit contact. Do we really need to swap fist bumps instead of kisses to protect ourselves from the flu? Sewell Chan, from our partner the New York Times, joins us to discuss the risks in greetings.