Philip Seymour Hoffman walking with a friend in Chelsea ... Carla Bruni blowing a kiss to photgraphers outside the Letterman show ... Rihanna arriving at JFK ... Naomi Watts walking in SoHo ... Keanu Reeves carrying a Barneys bag in Central Park ... James Franco leaving the New York Times building and later arriving at Letterman's studios ... actor Emile Hirsch walking with friends ... Katie Holmes leaving the Schoenfeld Theatre after a performance ... and a spandex-clad Robin Williams riding his bike at night.