Late Show with David Letterman: Season 3, Episode 47
Dave uses the speaker phone to get someone to bring him pizza. Later, thirty folks show up with boxes, and slices are handed out to the audience. Also, the United States is in the middle of a government shutdown, so Dave calls the Pentagon, misdials, finally gets an answering machine, and hangs up. A stagehand gives him an ax, cuts the phone cord, and hands the phone to an audience member.