There’s nothing like watching big-name talk show guests with bad movies to plug.

Take two examples from this week: Jim Carrey and Steve Martin.

Two of the biggest names in comedy worked Letterman, Conan O’Brien and Regis this week in support of two crummy movies: Carrey’s Fun With Dick And Jane and Martin’s Cheaper By The Dozen 2. (Carrey’s Fun co-star, Tea Leoni, guests tonight at 12:35 a.m. CBS/CH’s The Late Late Show With Craig Ferguson.)

Now, keep in mind, I’m no film critic. But your name doesn’t have to be Kirkland, Braun or Slotek to know that, three months from now, there’ll be a wall full of these titles at Blockbuster. See Kong, skip the other remakes.

Carrey and Martin both presumably fulfilled contractual obligations by working the talk show circuit and dutifully plugging these multi-million-dollar epics. Their approach to this task, however, couldn’t have been more opposite.

Martin seemed all sheepish and embarrassed on Live With Regis & Kelly, repeating the same lame joke he told the week before on Jay Leno (something about coming up with the title by adding the “2” at the end of Cheaper By The Dozen 2. Ha ha.). Maybe headlines like, “Laughs are rare in Martin’s latest sellout sequel” had him in a subdued mood.

Carrey, on the other hand, was at his gymnastic best, hopping around the Letterman stage like Tom Cruise at a couch testing.

The inner-club comic always comes out whenever Carrey visits old pals Letterman, Leno or O’Brien. Ask any of them to name their favourite talk show guest and Carrey’s name will be near the top of their lists (as, to be fair, would Martin’s). Like Robin Williams, he never fails to put on a show.

On Monday, Carrey literally stole a crazy wool Christmas sweater right off the back of a poor shivering gent in Letterman’s audience, leaving him topless. With the thermometer set at a crisp 55ºF inside the Ed Sullivan Theater, Carrey could have been charged with manslaughter.

Letterman, who has sat opposite enough stiffs, was only too happy to let Carrey go nuts. He laughed when Carrey volunteered to set up the clip and then turned himself into a movie projector.

(Another Martin/Carrey comparison: The Clip. Martin just sat and looked pained after seeing himself do Chevy Chase-level pratfalls on a lame Cheaper By The Dozen clip. Carrey’s happy and excited no matter how bad the clip. “I love looking at me,” he gushed.)

The next night, the Ontario-born comedian took over O’Brien’s show (much as he did in early 2004 when O’Brien featured Carrey during his week of Toronto tapings). While Carrey was crowing about how his film will kick King Kong’s blockbuster butt, the giant ape could be seen scaling O’Brien’s cardboard Empire State building in the background.

Carrey leapt out of his seat and ran off camera only to re-appear in miniature climbing up the other side of the building. Cut to Carrey and Kong mano-a-mano at the top of the tower. Around the corner comes those two bare-chested cowpokes from Brokeback Mountain and suddenly everybody is very Village People.

There you have Carrey in late night — tearing some dudes sweater off in a spontaneous act of live-and-dangerous theatre and throwing himself into a carefully scripted special-effects skit. The guy just gives and gives.

It almost makes you want to see his movie.