Sideshow: Dipping a toe into motherhood

Jennifer Aniston

hasn't lost her sense of humor even though she is ticked over the flurry of tabloid reports that she is pregnant.

"It's hysterical," the former

Friends

star tells Entertainment Weekly. "It's almost going to take away the fun from actually being able to say one day, 'I'm pregnant.' "

Jen does say it was fun to play a mother in her new flick,

Marley & Me

, an adaptation of former Inquirer columnist

John Grogan

's love letter to his dog. (The flick opens on Christmas Day.) The role, she says, made her yearn to be a mom. (Yes! Even celebs pine and yearn.)

"I feel like [having a baby is] in my future and I'm on the verge of it in some way - or it's something I long for," she explains. "So it was great to sort of dip your toe in it."

Jen refused to discuss any men in the interview, including ex-bf

Vince Vaughn

, ex-hubby

Brad Pitt

, or new bf

John Mayer

, except to say she's sick of the media war waged on her behalf against Brad and his new woman,

Angelina Jolie

. "That divide-and-conquer thing is stupid. It's just catty," she said. "I'm not catty."

Today in

Tina Fey

News, the AP reports that

Mad Men

star

Jon Hamm

(he plays ad exec Don Draper) is taking a temporary break from the AMC show to do a multiple-episode arc on NBC's

30 Rock

. He assays a juicy role as a love interest for Tina's character, Liz Lemon. Hamm will ham it up (

get it?

) as a devilishly handsome physician who lives in Liz's apartment building.

Never understood why stars who make tens of millions of dollars a year

and

pick up tens of thousands of dollars' worth of freebie luxury goods

still

sign up to do ads.

London's Daily Mail says

Madonna

(net worth $445 mil), who made $91.5 mil just from the North American leg of her tour, has done a print ad for Louis Vuitton. M., who looks a little like a haute-couture streetwalker, "poses seductively on a chair while holding a leg up - wearing fishnet tights, a tailored jacket and stilettos," says the Mail. Madge's fee?

$9.5 mil

.

Just as the dust has begun to settle around the

A-Rodonna

scandalette that saw

Alex Rodriguez

reportedly ditch his wife,

Cynthia

, for Louis Vuitton pinup Madonna, In Touch Weekly asks, "Is A-Rod cheating on Madonna?" (I can see the new headlines: "Third baseman rounds the bases with another beauty!")

The mag is weak on facts: An anonymous source says A-Rod recently partied with buds at a Miami club where he asked a "sexy female partier for her phone number." (Maybe he's interviewing babysitters for his two girls?)

There's more! In Touch reports friends of

Melissa Britos

say A-Rod has been seeing the Wilhelmina model on the sly. The mag hasn't solicited comments from A-Rod or Madonna.

In far less important - and, alas, entirely unsalacious - news, former President

Jimmy Carter

, who aroused some controversy with his last book on the Middle East,

Palestine: Peace Not Apartheid

, which compared Israeli-controlled Palestinian territories with apartheid-era South Africa, has written a new book on the subject that he says will incite friendlier discussions. Carter, who helped bring about a peace treaty between Israel and Egypt, said on Wednesday night that

We Can Bring Peace to the Holy Land

will be published shortly after the inauguration of

Barack Obama

.

"I was going to call it

Yes, We Can

. My wife talked me out of it," quipped Carter, who would not share any other details about the book.

Showtime says it is shooting 12 third-season episodes of

David Duchovny

's dramedy

Californication

, a low-cal (

Norman Mailer

-lite) version of that perennial literary theme,

serious-writer-is-inspired-(or-hopelessly-waylaid?)-by-cheap-booze-&-cheaper-sex

. Look for it in late '09.