LOS ANGELES — Being named Playboy magazine's 2007 Playmate of the Year made Sara Jean Underwood feel sick.

"I thought I was going to puke," she told The Associated Press. "I thought I was going to faint. I thought I was going to cry. It was every emotion you can imagine one would feel when given such an honor."

The petite 23-year-old blonde beat out 11 other beauties to become the magazine's 48th Playmate of the Year.

Her title and the start of her yearlong reign were celebrated Thursday with a backyard luncheon under a tent at Hugh Hefner's famous Playboy Mansion, with the yard filled with current and former playmates, more than 50 dating back to the 1950s.

Hefner called the event "one of my favorite days."

As founder and editor of the magazine, he helps select the annual honoree with advice from his promotions and photo staffs and oodles of input from readers.

And what they're looking for, he said, has been "essentially the same" since the first Playmate of the Year was crowned in 1960: "Women are a little healthier, a little slimmer, but it's always been, and was from the very beginning, the girl next door."