Your thoughts on teaching Abstinence or Safe Sex to teens? Which one?

There is a lot of recent thoughts about having kids abstain completely from sex until marriage. And no matter how noble a thought that is, is it really preparing teens for the future? I don't think kids should run out there and have sex but I do believe in providing the tools and knowledge they need to make that decision. My mom taught me about feelings I would have and what could happen should I have sex young. I in turn made my own decision not to have sex until I was at least out of school. So ingrained in me was my mom's voice telling me that when I do have sex with a guy I should prepare myself for being attached to him for at least 18 years should I get pregnant that I have had 5 sexual partners in my lifetime, and I'm 30 this year. My current guy and I have been together for 9 years consecutively. But I'm not a fan of waiting all together until marriage. Sex is a big part of marriage, so what if it isn't good, what if the couple's natural chemistry just doesn't sync, then you're stuck in a sexless marriage? I mean, we test drive cars and we only expect to have them for 10 years or so, marriage is for life. Wouldn't you want to test the waters before diving in? I just wanted some thoughts on the subject, tell me why you are for or against it.