The show often featured quirky, genre-mocking regular features, including “Stupid Pet Tricks” (which had its origins on Letterman’s morning show), Stupid Human Tricks, dropping various objects off the roof of a five-story building, demonstrations of unorthodox clothing (such as suits made of Alka-Seltzer, Velcro and suet), a recurring Top 10 list, the Monkey-Cam (and the Audience Cam), a facetious letter-answering segment, several “Film[s] by My Dog Bob” in which a camera was mounted on Letterman’s own dog (often with comic results) and Small Town News, all of which would eventually move with Letterman to CBS.
Other memorable moments included Letterman using a bullhorn to interrupt a live interview on The Today Show, announcing that he was the NBC News president
and that he was not wearing any pants; walking across the hall to Studio 6B, at the time the news studio for WNBC-TV, and interrupting Al Roker’s weather
segments during Live at Five; and staging “elevator races”, complete with commentary by NBC Sports’ Bob Costas. In one infamous appearance, in 1982, Andy
Kaufman (who was already wearing a neck brace) appeared with professional wrestler Jerry Lawler, who slapped and knocked the comedian to the ground (though
Lawler and Kaufman’s friend Bob Zmuda later revealed that the event was staged).