LOS ANGELES —  She's the biggest-selling "Idol" to date, so naturally Carrie Underwood is very defensive of the caustic critic who contributed to her big win three years ago.

"His [Simon Cowell's] role, I guess, is to be the 'bad guy,' so I get so, so angry when I see contestants up there arguing with him," Carrie told us backstage at Sunday's taping of "Idol Gives Back." "Just take it — get up there and take it like a man."

But while you can take the girl out of the country, you just can't take the country out of the girl. Underwood narrowly missed tripping on her ball gown as she climbed the stairs, proving that couture still isn't totally comfortable for her. And she sticks to basics in caring for her beauty.

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"I really don't buy anything expensive or do anything to look after my skin. It's actually really bad at the moment," Underwood told us quietly. "I just use soap and water. That's it."

Adrian Grenier's New Girl; Nicky Hilton's Romance Gets Serious

Australian-based surfing gang the "Bra Boys" premiered their self-titled documentary in West Hollywood on Monday night, but they weren't the only Aussies taking the States by storm.

Video: Bra Boys Premiere

Adrian Grenier attended the star-studded premiere and after-party, but there was only one gorgeous gal in his "Entourage." Grenier spent the night networking and schmoozing alongside his new leading lady, Australian actress Isabel Lucas.

Lucas is one of those quiet, totally natural-looking beachside beauties with an obvious passion for animal rights. Accompanied by Hayden Panettiere, Lucas visited Japan late last year to protest dolphin hunting by paddling out to stop the fishermen, and as a result a warrant has been placed for her arrest due to a "violation of international commerce."

But in Hollywood this week, it was nothing but adoring eyes for Izzy and Adrian. Speaking of couples who just can't leave each other's side, we also spotted Nicky Hilton and her beau, Dave Katzenberg, several times throughout the night (and later at Hyde) and not in a single sighting were they alone.

"They're very close," an insider source told Tarts. "I wouldn't think wedding bells are too far away."

Brandon Davis was (strangely) on his best behavior at the bash, and we're proud to say he didn't live up to his "Greasy Bear" branding as he actually looked clean while posing for pics with his, er, fans.

In fact, Davis actually looked decent (and much thinner), so much so that they even let him into ultra-luxe Hyde for the after-party.

Sadly, however, we missed the presence of the film's narrator, Russell Crowe, who used the "excuse" that it was his birthday and that he couldn't venture from his hotel down the road to rage on. (Let's hope it was phone-free!) But one thing about our "Beautiful Mind" man is that everything is physical — even business.

"He wasn't too keen on being involved when I first asked him," said the film's star and director, Sunny Abberton. "He gave me half an hour of running around the park to pitch it."

Well, running coupled with some crude words.

"He rang me and I didn't believe it was him, so I called him some bad words and he called me much worse words back," fellow star and pro-surfer Koby Abberton added. "I felt like an idiot when I found out it really was Russell."

New Miss Nevada Dating Criss Angel

Miss USA Rachel Smith and her sash sister Miss Teen USA Hillary Cruz led a big bevy of beauties (51, to be exact) into Andrea Patrick’s "On Top of Cloud 9" dinner at Maggiano’s Little Italy in Sin City last week, the entire pageant pack donning T-shirts with inspirational messages.

Cruz and Smith gave the gals a good ol’ earful of motivational tips such as ‘"just be yourself" (yawn) while the tiara-hopefuls did more than just pick at the high-protein goodies on their plates.

Even with the prospect of having to strut in a bikini in front of a worldwide audience looming, we’re told not a single contestant hesitated at tucking into a super-sized slice of chocolate cake with ice cream.

While everything seems so sweet and serene on the outside (with no stories of pepper spray or stealing costumes to emerge just yet), we can’t help but wonder if the new Miss Nevada, Veronica Grabowski, has a naughty side a la Katie Rees. Grabowski just so happens to be the new love for magic man Criss Angel — who knows what tricks those two have been cooking up.

(Tarts also has been told that Angel is launching his very own "Mindfreak" bar inside LAX nightclub this Friday, coinciding with the Miss USA crowning.)

More gossip ... it seems as though things between Carrie Underwood and "Gossip Girl" guy Chace Crawford may have been more serious than we thought. Chace’s baby sister, Candice, who is Miss Missouri, also attended the deluxe dinner, and we’re told she expressed her excitement that her brother would be in Sin City to cheer her on come Friday.

"The two of them are very close — Candice was very supportive through Chace’s break-up with Carrie, which was obviously very difficult," said an inside source. "She can’t wait to see him."

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