LOS ANGELES (Reuters) - Teen star Miley Cyrus wears one, so does "American Idol" winner Jordin Sparks and the members of the hit boy band The Jonas Brothers.
But it took the ridicule of a British comedian at a music awards show this week to highlight the entry of purity rings into the old equation of sex, drugs and rock'n'roll -- minus the drugs.
Purity rings, also known as chastity or promise rings, are worn by tens of thousands of young American teens who have pledged to remain virgins until marriage.
Originating in the United States in the 1990s among Christian groups, the rings are embossed with words like "True Love Waits" or "One Life One Love" and are worn by both sexes.
The concept has increasingly entered the world of pop rock music that once was the dominion of teen rebellion, and that fact perplexed Russell Brand, the anarchic host of Sunday's MTV Music Video Awards show in Los Angeles.
"It is a little bit ungrateful because (the Jonas Brothers) could literally have sex with any woman they want, but they're just not going to do it!", Brand told the audience. "That's like Superman just deciding not to fly, but to go home on a bus."
Sparks, 18, stood up for teen heartthrobs Kevin Jonas, 20, and his brothers Joe, 19 and Nick, 16, telling a cheering audience of rock stars. "I just wanna say, it's not bad to wear a promise ring because not every guy and a girl wants to be a slut, OK?"
Denny Pattyn, an evangelical pastor who founded the Silver Ring Thing 12 years ago, says celebrities can both help and hurt his group's quest to create a cultural shift in America where premarital abstinence becomes the rule rather than the exception.
Britney Spears once wore one and so did singer Jessica Simpson, who said she kept her pledge before her brief 2002 marriage to Nick Lachey.
"The Jonas Brothers, Jordin Sparks, Miley Cyrus -- they are doing a great job so far," Pattyn told Reuters.
Disney actresses Selina Gomez, 16, and Demi Lovato, 16, also wear purity rings.
"But when a celebrity has maybe put the ring on without the right education and inspiration and then they go out and do something crazy, then it's a reflection on us."
Pattyn said that wearing a ring is a constant reminder to stick with the promise.
"It is a commitment, like a wedding ring. It is more likely to work," he said.
The Silver Ring Thing, which runs high energy music stage shows encouraging 12-18 year-olds to take an abstinence pledge, is expanding its U.S. programs to South Africa, Brazil, Britain and Romania to meet public demand there.
Critics applaud the principle but say the problems arise when young Americans grow up, and are often ignorant of how to manage contraception and sexual health when they do decide to have sex.
"It is probably a nice thing that we have celebrities who are trying to be role models and model healthy behaviors," said Michael Reece, director of the Center for Sexual Health Promotion at Indiana University.
"But these abstinence pledges leave people completely unprepared, once they make the decision to become sexually active, and what happens is that we have a society that is sexually illiterate," Reece told Reuters.
Editing by Patricia Reaney