PHOTOS: Katherine Heigl, Quick-Change Artist

Katherine Heigl needed the perfect dress to show off her new, shorter 'do before Monday's Late Show with David Letterman, so when the Ugly Truth star showed up not-quite ready for the fans and photogs, she rushed inside the Ed Sullivan Theater to change.

Katherine, who recently lived through a minor bomb threat at the hotel both she and co-star Gerard Butler were staying at, emerged minutes later in a bright blue dress, looking very relieved as she posed for the cameras and spoke to her fans.