I really wish that sex-ed programs would talk more about the emotional aspects of sex. Granted, I strongly believe that parents should really be teaching this stuff to their kids, but the truth is that a lot of parents just hope (blindly maybe) that the school system will do their job for them.
I think it's important, especially during the teenage years, to not talk down to kids. Be honest about the normal urges that teens face and offer solutions beyond astinence only. It seems weird now to think about it, but I really never had someone tell me as a teen girl "you know, you can make out without having sex". When you talk about all sexual contact in a black and white kind of way, I think it leaves out all the middle-ground safer activities.
Also, I just wanted to share an exercise that we did in jr. high that still sticks with me today:
We were all seated around in a big circle and given index cards that had codes at the top and then we were told to get other people in the circle to sign our cards for 5 minutes.
After 5 minutes, we all sat back down. Then, the teacher asked everyone who had an A on their card to raise their hand: these people were "HIV +" and got a stack of red stickers cut into 1/4ths. Then, we went around the circle and anyone who had these people's signatures on their card got pieces of a sticker. How much of a piece you got depended on the code on your card. If you had a U, it meant you'd had unprotected sex and you got a whole sticker, if you had a C it meant you'd used a condom and you got 1/4 of a sticker, if you had a W it meant you'd used the withdrawl meathod and you got 1/2 a sticker, etc.
If you ended up with a whole red sticker (either all at once, or from accumulated peices) it meant you'd gotten HIV.
The stickers were handed out in the order of the signatures on your card, so it was possible to have a partner "get HIV" after you'd already "had sex" with them, etc.
When we were done, almost half the class had HIV from our little "orgy". It was very eye-opening. I still remember that I had a card with a U and had 5 signatures, but ended up with only 1/2 a sticker. (2 of my partners had 1/4 stickers, just my dumb luck) It was pretty scary.
The only people who didn't get any stickers were a few people who'd used condoms and 2 girls who were "monogamous" and had only signed each other's cards.