When Lewis and Martin split, a lot of observers believed Jerry would bomb and Dino would survive -- that the former's juvenile shtick would fall flat without the latter's suavity. In fact, both survived. Lewis directed and starred in hits for decades (in recent years in “Damn Yankees”), and Martin managed years as a singer, movie actor and host of his own TV variety show.

A sadder fate awaited Abbott and Costello, the most successful movie comedy team of the '40s who split in 1956. By himself, Lou Costello made only one picture, the forgettable “The 30-Foot Bride of Candy Rock” just before his 1959 death. Bud Abbott briefly lent his voice to a 1966 cartoon series inspired by the duo.

Occasionally, teams hit, split and come back together. In the 1950s in Chicago, University of Chicago students Mike Nichols and Elaine May met and launched one of the funniest comic duos in modern show business. But in the '60s they split, both turning to directing and writing. Nichols in particular enjoyed huge success directing “The Odd Couple” on the stage and acclaimed films including “Who's Afraid of Virginia Woolf?” May's directing efforts include “The Heartbreak Kid” and “A New Leaf” (in which she also co-starred).

Almost against the odds, the team reunited in the 1990s, with Nichols directing and May writing the screenplays for “The Birdcage” and “Primary Colors.”

Kathy O'Malley and Judy Markey, a midday duo for the last eight years on WGN-AM 720, give another view of partnership.

“We took out life insurance on each other a couple of months ago,” O'Malley says. “We both felt we were boring on the radio without each other, that the chemistry is a third of the equation . . .”

“. . . And we're too old to make a new friend,” Markey injects.

For now, both women are sold on partnership.

“In my professional life, I've always been part of a team,” O'Malley says. “For me, the positives outweigh the negatives. It's sharing the load, having someone understand what you do. I'm bad at being married, but good at being a partner.”

“I'm not a collaborative person by nature,” Markey says. “It's why I'd never write a screenplay. Too many people mess with your work. But since I was terrified of the radio domain, it was nice to have someone walk into it with you who was supportive.”

“Occasionally, we have shows with guest co-hosts, and it's different,” O'Malley says. “It's just not as much fun.”

“Around here we're referred to as `the girls,' “ Markey says without a hint of objection. “We're seen as one.”