Some of you are blowing the whole idea of these rings into something they are not.
They are a symbol. Nothing more, nothing less. They do not make someone "pure" no more than owning a Bible makes someone a Christian. The ring SYMBOLIZES a promise that a girl, boy, man or woman makes to themselves and to God. With out that promise and the ideas behind it, the ring means nothing.
It has nothing to do with a girl being "sullied" if she is no longer a virgin or that she should be pure at marriage while a boy doesn't have to. Its not even about being female. Boys wear purity rings too. It IS about what the wearer believes that God wants them to do and in the Christian faith, sex should only come within the sanctity of marriage.
Saying that a kid wearing a purity ring is going to make them more likely to have unplanned sex and not know about birth control, STDs, etc. has more to do with parenting than the ring. Wearing the ring does not stop anything and so the kid still needs to be taught the same things he/she would be without the ring. The ring only symbolizes that promise.
DD does not wear a purity ring. They have been talking about the idea behind the rings in her youth group-- they are talking to ALL of the youth, not just the girls (this is 7th grade and up). She has said that she wanted to look for one. She doesn't really like the bands, but was thinking about one that has a stone in it. Its completely her choice whether to wear this ring. And actually, I did suggest to her that if she chooses to wear a symbol it doesn't even have to be a ring, she could choose a cross necklace or a bracelet. Her symbol doesn't have to be one of these mass produced rings. It is something that is personal, between her and God and that can be symbolized by anything or by nothing at all.
If the wearer is in true understanding of what the ring means and the promise behind it, it should not matter whether anyone knows what it means or not. The promise is between the wearer and God--no one else. And if the wearer is secure in his/her faith and in what he/she believes then he/she should not have any issue explaining what it means.
Our church does not plan any kind of ceremony but I know another local church that did have one. There was no father giving the daughter the ring. They had a week long class with all of the youth and the single adults. At the end of the week, the people who CHOSE to wear the ring were presented the ring at a ceremony. It was done more like a graduation ceremony with each person receiving the ring from the pastor.
With all of that said, if dd had mentioned these rings at 11; my instinct would have been to talk to someone at the church and to let her talk one on one with them. I would need to be sure she understood the promise that is behind the ring and what it truly means. Just like her baptism, its not something that I would want her to take lightly.
And BTW, this ring isn't going to keep an unmarried adult from having sex unless that is what they choose. Lightening isn't going to strike them because they break that promise or choose to no longer feel the need to keep the promise. Again, its just a symbol.
As for the peer pressure thing, almost all teens are swayed in one direction or the other by peer pressure. Heck, most adults are too. Because a teen chooses to be swayed by positive peer pressure does not mean they will go the other direction. One thing that dd has been taught by us and by the youth leaders at church is to be careful of who she surrounds herself with for this very reason. If she is surrounded by people with the same morals and values as she, then its less likely that she will do something that is not within that value system.