Will Ferrell and Pearl Jam will be part of Conan O'Brien's first "Tonight Show."

Ferrell joined O'Brien in February for his final "Late Night" show in New York. The actor-comedian now will help O'Brien kick off his tenure on "Tonight" in Los Angeles.

Pearl Jam will be the first band on O'Brien's show, playing songs from an upcoming studio album, NBC said yesterday.

O'Brien takes over the late-night show June 1, after Jay Leno wraps up his 17-year run as "Tonight" host May 29. Leno is moving to a daily prime-time series for NBC in the fall.

ANEURYSM KILLED X-RATED MOVIE QUEEN

Marilyn Chambers, the famous adult-movie queen who passed away last month, died of natural causes, a Los Angeles coroner's spokesman said yesterday. An autopsy found that she died of a cerebral hemorrhage, with a "ruptured cerebral artery berry aneurysm." Final autopsy results will be available in several weeks.

Chambers, whose real name was Marilyn Ann Taylor, was found unconscious April 12 at her suburban home.

Chambers became a pop culture phenomenon when she starred in the X-rated "Behind the Green Door" in 1972, prompting Procter & Gamble to pull boxes of Ivory Snow soap, then graced by her angelically complexioned face, off the shelves.

CYNTHIA NIXON ENGAGED TO GAL PAL

Cynthia Nixon is engaged to Christine Marinoni.

Charlotte Burke, a representative for the "Sex and the City" actress, confirmed the engagement. No other details were given.

Nixon, 43, showed off an engagement ring at an Action-Equals-Marriage Equality rally Sunday in midtown Manhattan.

She has two children from her relationship with photographer Danny Mozes.

PERU TEENS MOB JONAS BROTHERS' HOTEL

Peru has called out riot police to control hundreds of young girls swarming the hotel where the Jonas Brothers are staying. Thousands of other fans have lined up for tickets for the group's world tour premiere.

The boy band is performing two concerts in Lima because a Mexico concert was postponed due to the swine flu epidemic there. The first Lima concert sold out in hours and 60,000 people were expected for each show, yesterday and today.

EMINEM TO PLAY FREE DETROIT SHOW

Eminem is planning a free show in Detroit today, the day his album "Relapse" is released.

He announced plans for today's show on his MySpace page. Fans lined up for tickets yesterday morning at Record Time in the Detroit suburb of Roseville, reportedly snapping up nearly 500 tickets in about 45 minutes.

DJ Jazzy Jeff will guest at the show in MotorCity Casino's 1,500-seat Sound Board theater.