Late Show with David Letterman

Tonight's "Great Moments in Presidental Speeches" clip is doctored to include Sue Hum using a lint brush on JFK's right arm; Duke University post-grad John Cornwell demonstrates his new invention, the beer-launching refrigerator; Jack Black shares an antedote about meeting Jack Nicholson; CBS chief foriegn correspondent Lara Logan discusses reporting from war zones in Iraq and Afghanistan.