Regis Philbin‘s will take a bow on his last show Friday morning, but, before leaving, he paid old friend David Letterman a visit on Thursday night, discussing he kiss they shared on air a day earlier and having the Top Ten list dedicated to him. As a parting gift, Letterman mounted Regis on a new red vespa scooter, and encouraged him to ride off into the sunset on it. One problem: Regis had never driven one before. He accelerated, wobbled, then tumbled the mini-motorcycle, eventually jumping off just in time to avoid a nasty and untimely accident.

Bill O’Reilly appeared on David Letterman ostensibly to promote his new book Killing Lincoln, but the conversation turned to a variety of items in the news:Occupy Wall Street, The Tea Party Movement and $16 muffins all got some airtime in a spirited and light back-and-forth. But the most tense part of the exchange was a surprisingly dramatic high-five between the two influential television personalities who have not always seen eye-to-eye, but put aside any previous tension for a symbolic demonstration of agreement. The harmonic convergence is now upon us!

President Bill Clinton appeared on the Late Show with David Letterman last night and discussion of the Occupy Wall Street protests proved to be as interesting a recap as one might expect. The former president was generally very supportive of the movement, however he did not seem entirely impressed with the specific message currently coming from the protestors, summing up by saying “you need to be for something, not just against something,” before drawing comparisons to both the Tea Party and the Arab Spring.

David Letterman and his guest Dr. Phil discussed Donald Trump‘s recent allegations that Barack Obama was admitted into Ivy League schools despite being a very poor student. Letterman joined many other media personalities who have criticized Trump’s suggestion as being racist, though Dr. Phil defended Trump, saying that he’s “not a racist.” Letterman made then, perhaps the deepest cut, when he openly considered not inviting Trump back on his show until he apologizes.

Taking the risk in assuming people who watch reality series can also read, Nicole “Snooki” Polizzi, star of MTV’s Jersey Shore, has released a novel entitled A Shore Thing. While the book will eventually be required reading for all college literature classes (an entire week of discussions will be used to analyze just the pun in the title alone), right now, it just needs to sell. So, Snooki showed up to deliver the Top 10 on the Late Show last night, listing ten reasons why you should read her opus.

Last night on the Late Show, Tina Fey gifted David Letterman with a few moments of her infamous Sarah Palin impression. She also got a swipe in at Fox News, saying they should stop calling her “Governor Palin” because it would be like still introducing Fey as a “Dairy Queen employee.” It was a good line if you excuse the fact that we do that for all political figures. Still, any Fey as Palin is better than no Fey as Palin.

Ah, this could be fun. Last night, David Letterman used the Fox & Friends jetpack gaffe as a springboard for a Top 10 list of “Signs There’s Trouble at FOX News.” While the segment’s barbs never got any more critical that insinuating that Bill O’Reilly was going to institute a “No Pants Zone,” NewsBusters picked the story up and now Sean Hannity is going to run with it. Set your DVRs for “mildly amused!”

NBC Nightly News anchor Brian Williams was a guest on CBS’ Late Show with David Letterman last night and the cross network appearance was a major theme of the discussion.

From the very first question, Letterman (armed with his Jay Leno impression) joked at his rival’s expense while Williams played the role of mediator.

MSNBC’s Rachel Maddow was back on CBS’ Late Show with David Letterman last night, and the pair discussed how much her guest host Chris Hayes looks like her.

But the main topic was, “why is CNN just about out of business?”

Robert Halderman, the former CBS producer now serving jail time for his failed attempt to blackmail David Letterman, finally received some good news in his cell today, but, unfortunately for him, it had nothing to do with his sentence: he’s nominated for an Emmy.

For the first time in 10 years, ABC News “Nightline” beat out CBS’ “Late Show with David Letterman” for total viewers, as well as in the A25-54 demographic, in the second quarter. The last time Nightline outperformed Letterman was in 2000.

The late-night news program also had its most second quarter viewers in six years.

After collaborating in the Jay Leno-bashing during the NBC late night wars, David Letterman and ABC’s Jimmy Kimmel reminisced on the experience during Kimmel’s guest spot on the CBS late show last night.

Both described it as “fun,” but only Kimmel was armed with a few more jabs.

Before former Chicago Governor Rod Blagojevich begins his run on NBC’s reality show Celebrity Apprentice, he stopped by CBS’ Late Show with David Letterman for some cross-network promotion.

Blago got his shot at Letterman’s top 10 list – “questions asked himself before appearing on Celebrity Apprentice.”

In a 180 degree reversal from when his lawyer made the media rounds last year, the CBS producer accused of attempted extortion of David Letterman will plead guilty today and serve six months in jail.

Robert Halderman and his lawyer had previously maintained his innocence, but now he’ll take a plea deal.

Morning Joe, the most laid-back cable news program this side of Red Eye, may not be the first place to look for a call to arms against beer-and-chips gag ads on the Super Bowl, but guest Donny Deutsch took the opportunity to remind companies that football fans are not as dumb as they might think.

Negotiations between Conan O’Brien and NBC recently hit a snag over Tonight Show staff compensation, as the $40 million or so NBC is reportedly paying Conan not to do The Tonight Show apparently has the network a bit reluctant to shell out anything more. However, even if and when the two sides work that issue out, another complication, referenced by O’Brien on last night’s show, looms – intellectual property.

While the NBC infighting continues, the jokes are still coming in from around the late night spectrum – and specifically from the most vocal late night host so far, David Letterman.

Letterman previewed a promo of the “new” old Tonight Show, and knocked Jay Leno‘s “State of the Network” speech from Monday.

As he has all week, David Letterman took obvious delight in ripping NBC and its late night situation on his CBS Late Show.

But last night he went specific – taking aim at NBCU President Jeff Zucker and other “idiot” NBC executives.

David Letterman didn’t hold back, again, in bashing NBC and its late night woes on his Late Show tonight.

But in a move that combined new media savvy, playful ribbing and the acknowledgment many viewers would be tuning into the potential impending seminal late night moment when Conan O’Brien post-letter Tonight Show airs, CBS released all portions of Letterman’s NBC jabs early on YouTube.

Stephen Colbert became a huge star by adopting a personality radically different from his own, but since he and his fake pundit character share a name, the intertwining of the two Stephen Colberts was inevitable. Add in the high-profile public appearances he’s made in character, and it’s no wonder it can be a shock to the system when the real Colbert drops the blustery veneer, as he did last night on Late Show with David Letterman.

David Letterman appears to be reaping the rewards of the National Enquirer‘s new found respect — or perhaps fear factor is a better way to phrase it. No one wants to miss a story as big as John Edwards ever again. Behold: The Letterman Sex Tape.

Shortly after news of the Letterman scandal broke (you may recall that it was broken by intrepid reporter David Letterman), Nikki Finke theorized that CBS wouldn’t investigate it because CBS boss Les Moonves and his boss, Sumner Redstone, had both had adulterous affairs, and so they wouldn’t be too keen on digging into Letterman.

But as the New York Observer‘s Felix Gilette reports, CBS will be looking into the sex-and-extortion saga the way they know best: with a crack investigative reporter.

Is the journalism industry so down at the mouth these days that David Letterman is the only thing standing between it an utter irrelevance? Probably not, but you’d be forgiven for drawing that conclusion based on how much ink the Late Show host’s love life continues to generate. How much more can we read before utter boredom with the ‘scandal’ sets in.

Last night, after a weekend of being battered by the press, David Letterman apologized on air to both his wife and his staff. The part that struck as a strange and insincere admission? That he didn’t see the tabloid frenzy coming. Did Dave just move to New York City?

Based on the coverage David Letterman‘s alleged love life is getting these days you’d be forgiven for concluding that Letterman wasn’t the victim of a $2 million extortion plot but the subject of an undercover investigation or sexual harassment lawsuit. Accuracy seems to be taking a back seat to scandalous headlines.