Sideshow:

Oprah

's powers know no bounds. Forbes has anointed the talk-show host the most powerful celeb on earth for the second year in a row and the fifth time ever. Forbes' Celebrity 100 list also includes

Tiger Woods

(No. 2) and

David Beckham

(No. 5). It features two power couples:

Angelina Jolie

is No. 3; her man - and

Chris Martin

's perennial obsession -

Brad Pitt

is No. 10; and the recently wed beauties

Beyonce Knowles

and

Jay-Z

are Nos. 4 and 7, respectively.

Two-time Oscar winner

Kevin Spacey

, 48, who has been artistic director of the prestigious Old Vic theater in London since 2003, will head to Oxford in October for a new gig as a teacher. The university announced Friday that he would succeed Shakespearean actor

Patrick Stewart

as the Cameron Mackintosh Visiting Professor of Contemporary Theatre at Oxford's St. Catherine's College. Spacey, who will give lectures and lead seminars and theater workshops, said he was honored by the appointment.

Jon Voight

has been given 24 hours to kill

Kiefer Sutherland

.

Angelina Jolie

's estranged dad, who hasn't done a TV series in 40 years, will join the seventh season of Fox's spy thriller,

24

, as a recurring character described by the Hollywood Reporter as "the über-nemesis of" Kiefer's character, Jack Bauer. A two-hour prequel to the new season is scheduled to air Nov. 23.

Looks like

Chris Martin

, 31, beloved singer, husband and father, is feeling a bit insecure lately.

The

Coldplay

rocker tells Rolling Stone that it ain't easy to live in

Brad Pitt

's shadow - or, for that matter, in wife

Gwyneth Paltrow

's.

"Being married to someone very successful and very powerful basically keeps you hungry to improve," Chris says. "If your wife went out with Brad Pitt, you'd want to prove yourself, you know what I mean?"

He also confesses, "I had a tricky time with girls until I was, like, 21."

Things got ugly for Gwyn's scruffier half Thursday when he walked out of an interview with BBC's Radio 4 after nine minutes. "I just don't really like having to talk about things," he said, perhaps not realizing he was doing an

interview

.

Things got bad when Chris was asked why his band was fascinated with death. (Its latest CD is

Viva la Vida or Death and All His Friends

.) "I wouldn't agree with you," said Chris, who accused the show's host of "journalistically twisting me into saying something I don't really mean."

Meanwhile, Reuters reports that Coldplay's new disc sold a whopping

125,000 copies

on the first day of its release in the U.K.

So, will

Queen Latifah

, 38, ever have kids?

"Oh, yeah, yeah, yeah, yeah!" the rapper-turned-actress told OK! "There's the intention. I don't know when, but it's going to happen. It's going to have to happen eventually." QL chatted with OK! Wednesday at the League National Awards and Recognition Luncheon, which recognized her work with the League, a new youth-service organization in her hometown of Newark, N.J.