On his final "Tonight" show yesterday, Conan O'Brien said walking away instead of accepting a demotion is the hardest thing he's ever had to do.

Despite the rancor that led to his $45 million buyout, the red-haired comic urged fans not to be cynical and said their support made a sad situation "joyous and inspirational." He thanked his viewers and even NBC for more than 20 years of employment but not before getting in a few final jabs in his monologue.

O'Brien will be replaced March 1 by the man he took over for seven months ago — Jay Leno. In the interim, reruns will fill the slot, followed by Winter Olympics programming next month.

"Every comedian dreams of hosting the 'Tonight' show and, for seven months, I got to," he said.

JUDGE ORDERS POLANSKI TO RETURN TO U.S.

A Los Angeles judge ruled yesterday that Roman Polanski must return to the U.S. to be sentenced in a decades-old sex case.

Superior Court Judge Peter Espinoza said he ruled "in defense of the integrity of the justice system, he needs to surrender."

Attorneys for the 76-year-old director have argued their client should be sentenced in absentia to time already served after pleading guilty in 1978 to one count of unlawful sexual intercourse with a 13-year-old girl.

Polanski, arrested on a U.S. warrant, spent more than 60 days in a Swiss jail before being transferred to house arrest in his Swiss vacation home Dec. 4.

LOWE SET TO LEAVE 'BROTHERS & SISTERS'

Rob Lowe wants to downsize his TV family.

The actor will leave ABC's "Brothers & Sisters" at the end of the season, his publicist, Nicole Perez-Krueger, said yesterday. It was Lowe's fourth year on the drama.

Lowe plays Sen. Robert McCallister, who is married to Calista Flockhart's character, Kitty.

This isn't the first time Lowe has left a role where he's part of an ensemble. He exited NBC's "The West Wing" in 2003 to star in "The Lyon's Den." The show was canceled after six episodes aired.

MINNESOTA VIKINGS INSPIRE PRINCE'S LATEST

Prince has recorded a purple-tinted tribute to the Minnesota Vikings.

The "Purple Rain" superstar told Fox affiliate KMSP-TV that he penned "Purple and Gold" after he saw the Vikings beat Dallas at the Metrodome last weekend.

The Vikings play the Saints in New Orleans tomorrow in the NFC championship game.

The hymn-like Vikings song from the Minnesota rocker includes the lyrics, "Raise every voice and let it b' known/in the name of the purple and gold."