Late Show with David Letterman

Water-balloon fiend Paul Thoresen drops a 55-gallon bomb on a convertable with three "tourists" (mannequins); the Democratic National Convention is over but Biff's still there; Amy Sedaris obsesses over Dave's shoe tassels; Kim Kardashian describes nearly losing her big toe and plugs Disaster Movie; Brian Regan does stand-up and promotes his upcoming TV special.