Some people will do anything to promote their new book. In the case of Jon Stewart, who's been out hawking "Earth (The Book): A Visitor's Guide to the Human Race," it meant spending a bunch of time Wednesday night with Bill O'Reilly on "The O'Reilly Factor." I don't know if Stewart sold any books, since the Fox News audience is not exactly his best fan base, but it was wonderfully wacky entertainment. Watching Stewart joust with Papa Bear was like watching a great buddy picture comedy team, their differences providing the perfect spark for the relationship.

Comedy teams are all about contrasts and opposing sensibilities, so you couldn't ask for more from this odd couple, who were strikingly reminiscent of Nick Nolte and Eddie Murphy in "48 HRS," with O'Reilly as the gruff, by-the-book straight arrow (that would be Nolte), Stewart as the sassy, wise-cracking motormouth (that would be Murphy, if he were white and Jewish).

Much of the discussion, since this is after all Fox News, revolved around Barack Obama's failings, though for Stewart, Obama's biggest failing was that he hadn't done enough to change America, while at Fox they are petrified of what precious little change Obama has wrought. When O'Reilly asked Stewart if he had bought the whole Obama "messiah thing," Stewart quipped: "I don't buy the messiah thing even with the messiah thing, let alone with a politician."

The talk also turned to the Delaware Senate race between Christine O'Donnell and Chris Coons, which O'Reilly, always willing to give the Democratic candidate the benefit of the doubt, dubbed a contest "between the witch and the Marxist." To which Stewart responded: "And by the way, that is by no means a pejorative way of describing him--I'm sure he's a Marxist."

The more I think about it, these guys would make a great Hollywood comedy team because they don't even need a pesky screenwriter to write their insults and retorts. It comes right out of their own mouths. When O'Reilly finally turned his attention to Stewart's new book, the "Daily Show" host contrasted it to O'Reilly's never-ending stream of political texts, saying "I put effort into my books. I don't put one out every six months from stuff I dictate on the way home." Perhaps just to annoy Stewart, O'Reilly began casually leafing through the book during the rest of the interview, prompting Stewart to blurt out: "Is this really the time to skim the book? ... Should I join you in the bathroom while you read it?"

It just kept getting better and better as it went along, like "Midnight Run" (where O'Reilly would handle the De Niro part and Stewart would do Charles Grodin). Really, I think it's time these guys took the act out on the road. They may not agree on anything when it comes to politics, but when it comes to comedy, they are up there in the buddy team pantheon. See some of their performance for yourselves right here:

Photo: Jon Stewart, left. with Bill O'Reilly, taping an interview for "The O'Reilly Factor." Credit: Peter Kramer / Associated Press