"Bikini Girl" Does Battle With Kara DioGuardi

Who knew that American Idol judge Kara DioGuardi had such a killer set of...pipes? She clearly blew away 21-year-old "bikini girl" Katrina Darrell in last night's season finale when she emerged with a microphone during Darrell's rendition of "Vision of Love."

DioGuardi, a noted record producer, surprised over 30 million viewers when she belted out the lyrics and then ripped open the buttons on her dress to reveal a killer set of curves.

Darrell's facial expression, upon realizing that the 38-year-old both out sang and out stripped her, was priceless. Good thing because the Idol castoff is probably down to her last penny after having mid-season boob job. "I was going to ask what's new," Ryan Seacrest said when Darrell took the stage, "but I think I know."

Boob jobs on American Idol are nothing new. Season 5 contestant Kellie Pickler also went under the knife after she was booted off the show. Although her rep denied the 22-year-old had any "facial surgery," it's pretty obvious, even from outer space, that the country western star was on the receiving end of a few knives and needles. 

So what's with 20-somethings getting botox anyway? Are they frowning more often or simply trying to keep up with a new breed of women, the super hot 40-something?

DioGuardi's strip tease is just one example of how older women are over shadowing younger girls by staying in shape. When a 20-year-old flaunts her flat abs, it's simply a matter of metabolism. But when a 38-year-old shows the world she's buff and beautiful, men take notice. Read: Sweat Together, Stay Together