O'Brien took a sledgehammer and ax to his stage set this week, giving fans souvenirs. On his last show, taped Friday evening and aired at 12:35 a.m. ET, a construction vehicle was used to tear down a pillar of lights, which was cut up offstage.
Most of his final "Late Night" after 16 years was spent airing highlights and visiting with Andy Richter, O'Brien's former sidekick who left the show in 2000. It was an excuse to air the priceless clip of Richter, "tricked" into believing he was going to a spa, wandering nude onto the "Today" show set and interrupting Matt Lauer.
"We're going on to this next gig and sometimes I read that it's time for Conan to grow up because he's going to 11:30," said the 45-year-old O'Brien. "I assure you, that's just not going to happen.
"This is who I am," he said, the roar from his studio audience's standing ovation drowning him out.
Some in the TV industry have questioned whether O'Brien's silly, absurdist humor would fly on the "Tonight" show. But the time slot is now a comfortable home to Stephen Colbert on Comedy Central and a popular lineup on The Cartoon Network that appeals to a coveted audience of young men.
Besides, current "Tonight" host Jay Leno will continue on an NBC talk show, moving up himself to 10 p.m. in the fall.
NBC has built a new studio for Jimmy Fallon, who replaces O'Brien beginning March 2.
Ferrell, who's starring a few blocks away from Rockefeller Center in a Broadway production as former President George W. Bush, stopped by in costume to offer a few mangled words of congratulations. But he stripped off his suit to reveal another character, a leprechaun stripper who rubs up against O'Brien's leg.
The White Stripes were his final musical guest, with the duo strumming guitars on "I Can Tell We're Going to Be Friends."