Late Show with David Letterman

During Mailbag, various staffers show the audience their baby pictures; Dave introduces a musical comedy troupe called ""The Beltway Bunch"" (a rip-off of The Capital Steps), and Tony runs them offstage; just before introducing tonight's ""Stupid Pet Tricks,"" Dave thanks Merrill Markoe (who underwent surgery earlier in the day) for giving him the idea to do this segment.