In a city known more for sin than virtue, a group of virgins from around the country gathered this weekend to send a message: wait until marriage.

It was a clash of the "Good Girls" and the sin-seekers as about 200 teens, parents and youth counselors descended on the Strip to pass out cards promoting abstinence.

"What better place to bring this than Sin City?" said participant Deanna Grimm, 24, of Sioux Falls, S.D. "They need to hear it."

About 750 people traveled to Las Vegas to attend the seventh annual National Abstinence Clearinghouse Conference (search), which runs through Sunday. Featuring seminars on the history of abstinence and the consequences of premarital sex, the convention's theme is "Beyond the Neon: Creating a Culture of Character."

Convention exhibitors displayed various abstinence items, including "Keep It" underwear depicting a large red stop sign with the message "No Trespassing."

"(Abstinence is) a very important message to spread to teens all over," said Grimm, who works for the Abstinence Clearinghouse. "A lot of kids don't know about the dangers of premarital sex."

The reception was mixed Friday night as the virgin brigade passed out about 5,000 "Good Girl Cards" to mostly female passersby, many clad in short skirts and low-cut tops. The event was designed to counter dozens of people who routinely hand out color ads for scantily clad entertainers and escorts on the Strip.

"I like being handed these (Good Girl Cards) more than the porn ones they usually hand out," said Corrie Bouma, a 23-year-old teacher's aide from Hawthorne, N.J., who was in town on vacation.

But Clare Rose disagreed with the group's message, saying it should focus more on sex education.

"They're being narrow-minded and naive," said the 21-year-old who was walking by with friends. "People in this day and age are not, not going to have sex."

But the movement has grown in recent years, with more than one million teens and college students registering their virtue with True Love Waits, one of several abstinence campaigns. While True Love Waits is a faith-based organization, the Sioux Falls, S.D.-based Abstinence Clearinghouse is not.

Many supporters cite increases in sexually transmitted diseases as reason enough to wait until marriage. Studies show that in the United States there are about 45 million cases of herpes (search), 20 million cases of human papillomavirus (HPV) (search) and 900,000 people living with AIDS (search).

"There's no condom on the face of this earth that can prevent HPV. It's so highly contagious," said Melodi Hawley, a 21-year-old director of a sex and family education office in Denham Springs, La. "And we're not told this. I tell kids, and they say, 'human papa-what?'"

A national study published last week by the conservative Heritage Foundation found that girls who begin sexual activity at age 13 are twice as likely to become infected by a sexually transmitted disease as girls who begin having sex at the age of 21.

The study also found nearly 40 percent of girls who start having sex at ages 13 and 14 will give birth outside of marriage. And they're more than three times as likely to become single mothers.

"The earlier a girl had begun sexual activity, the less likely she was to be happy in her life many, many years later," said Robert Rector, senior research fellow at the Heritage Foundation and a speaker at the convention.

For Luis Galdamez, a 36-year-old abstinence educator from Wildomar, Calif., it was important to stress that anyone can practice abstinence until marriage, even if you're no longer a virgin.

"It doesn't matter who you are, what you believe. It's your body. It's your choice," said Galdamez, who spoke at the event. "You're worth the wait."