Hello, Columbus

TUBE TALK Ready for the sight of Brad Pitt in a fat suit? He's guest starring in a November sweeps episode of ''Friends.'' He'll play a high school pal of Monica's who was once even heavier than she used to be, as viewers will discover in a flashback sequence. She invites the now-slim chum home for Thanksgiving, where he and Rachel cause friction. Which is ironic, since rumor has it that Pitt got the part because he's reportedly sleeping with Jennifer Aniston....

It's not quite the vote of confidence that a full-season pickup would be, but CBS has ordered six more episodes of the struggling ''The Ellen Show.'' Maybe the series will get a boost from Ellen DeGeneres' hosting of the Emmys on Sunday, which was the plan back when the awards show was scheduled for Sept. 16....

Danny DeVito is returning to TV, this time as a director. He's shooting a pilot of a family sitcom written by ''Simpsons'' scribes Bill Oakley and Josh Weinstein....

Conservatives have often complained about the perceived liberal bias of Geraldo Rivera, so maybe Fox News Channel has ulterior motives in sending him to the combat zone in Afghanistan. Rivera, whose final CNBC talk show is Nov. 16, has signed a four-year deal with FNC, where he'll serve as the channel's live correspondent from the front lines. ''I'm a reporter,'' Rivera told Variety, ''and America's fight against terror is the biggest story of our times. And as much as I loved my CNBC program, I can't stay anchored to that desk any longer.'' He still had a year to go on his CNBC contract, but when the channel refused to let him go into the field, he asked to be let go. Since CNBC wants to put a business-oriented show in prime time, it was happy to oblige him. Now he'll be working again for Roger Ailes, the Fox News chief who hired Rivera in 1994 when he was running CNBC.

BRIEF CASE James Gandolfini gave up his shorts recently, and not because Uma Thurman and Ethan Hawke are suing the pants off him for his allegedly backing out on an agreement to buy their New York townhouse. At a recent benefit for New York firemen, a fan approached Gandolfini and demanded his boxers. He told her she could have them if she donated $1,000 to the Firefighters Fund. She whipped out her checkbook, and the actor lit out for the men's room, returning with black boxer briefs in hand. He may play a timid colonel in the current ''The Last Castle,'' but he clearly wasn't afraid to go commando for the rest of the evening.