Paris Hilton is a very big deal Down Under, and the City of Sydney is getting ready for the blonde babe to make a blitz as the host of the Bongo Virus New Years Eve bash. But even though Prince William was invited to ring in 2009 at the wild affair, we’re told he’s been banned from hanging with the hotel heiress.

"William really wanted to go," a source close to the 26-year-old Prince said. "But he has been told under no circumstances is he to associate with Paris." Ouch.

A royal rep could not be reached for comment.

But it look as though there is going to be quite a few interesting guests at the highly-anticipated affair. Tarts has been told that Hilton’s co-star in that much-talked about homemade video, Rick Salomon, will also be in Sydney for a month and intends to hit up the hot party.

"Paris wasn’t happy when she found out he was going to be in town," said our source. "But he’s friends with people involved in the party and wants to go but won’t officially commit."

And even though Benji Madden hooked up with Hilton soon after splitting with former fiancée Sophie Monk, the Aussie blonde obviously doesn’t have any hard feelings toward the heiress as we’re also told Monk has told pals she too may attend. But could it be an awkward three-way reunion? Inside sources told Tarts that Mr. Madden still plans to head Down Under in December even though he will no longer be spinning at the bash and rumor has it he wants to win back Hilton (who is now taking little sis Nicky as her date instead).

"She won’t take him back," a Paris pal said. "She’s over it."

Cate Blanchett Regrets Wedding Day

She’s one of Hollywood’s hottest actresses and received her Star on the Walk of Fame just last week, but Cate Blanchett has one big regret in life -- she has nothing but metaphorical memories of her wedding to playwright Andrew Upton 11 years ago.

"The only moment of my life I would possibly recapture is getting remarried again because we didn’t take any photographs," Blanchett told Tarts at "The Curious Case of Benjamin Button" premiere in Los Angeles on Monday evening. "We didn’t have any money at the time and we couldn’t afford a photographer."

But working on the film in which a man ages backwards and is unable to stop time, Cate was forced to open up about some other pretty interesting moments.

"In rehearsal we were talking about our relationship with our parents, about the first time you kissed somebody, it makes you remember the turning points in your life," she added. "The thing I physically learned (for the film) was a lot of dance moves. I thought a lot about my grandmother because a large portion of the film I am playing an 86-year-old who is dying in bed."

Angelina Shows Off Super Slim Bod

Meanwhile Cate’s co-star Brad Pitt caused expected chaos when he showed up with lover Angelina Jolie, whose super slender bod contoured by a Versace strapless black dress made it hard to believe she gave birth to twins less than four months ago. The Tinseltown twosome stayed close throughout the evening, clearly refuting any rumors that their romance is rocky.

As Pitt worked the press line Jolie entertained his parents, but took time-out to reunite with Jennifer Lopez. Ang’s face lit up when she spotted the songstress strutting by and after a quick embrace Angelina promised they’d have more time to talk later.

And despite having over 60 film acting credits to his name, Pitt told Tarts that this drama was something totally new for him.

"I think Fincher (the director) has created something really really special here, something unique and unlike anything you have seen before but in the vein of this kind of classic epic story," he said. "This is the first film where an actor gets to drive the performance from birth to death so it’s a new direction."

But when he’s not entertaining the masses or entertaining his flourishing family, Pitt’s time is still dedicated to the victims of Hurricane Katrina.

"They need help, Katrina was not an act of God it was a man made levee failure and they have been left in limbo, they need some help," he said.

Alba’s Airbrushing Embarrassment

Stars want us to think they’re naturally slim and stunning, right? Well in some ways it’s nice to know that even Jessica Alba relies on technology to look as taught and trim as she does in pics. Before & After photographs of Jessica Alba’s shoot for the 2009 Campari Calendar (snapped by famed photographer Mario Testino) seem to show quite a bit of touching and retouching as her hips are almost gone and her bust is notably bigger.

Click to see.

Alba (who gave birth to Honor Marie in June) never made a secret of the fact she was uncomfortable with her pregnancy pounds as she refused to pose for pics and even told Cosmopolitan Magazine that she "couldn’t wait" to give birth so she could get her body back.

Ferrera & Sigler: It's Official

Jamie-Lynn Sigler and Jerry Ferrera have been attempting to go under the radar with their romance, but the Tinseltown twosome were anything but low-key at Switch Boutique in Beverly Hills on Tuesday night.

Sigler launched her new jewelry line CJ Free at the JETT Vodka/Switch holiday party, but seemed somewhat stressed until Ferrera finally arrived. The actress immediately rushed over to Ferrera and the two couldn't keep their hands off one another. But it looks as though their personal relationship could soon become professional as well.

Pop Tarts spotted Sigler in a very lengthy, super serious discussion with "Entourage" creator Doug Ellin (she appeared on the hit HBO series as herself) and an inside source told Tarts that a possible recurring role could be on the cards ...

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