Forgive me for butting in here, but you guys seems to be confusing the morning after pill with the abortion pill.
The morning after pill is taken within 72 hours of unprotected sex and prevents pregnancy by changing the chemical content of the lining of the uterus so the egg cannot attach itself. Actually the morning after pill is a high dose of birth control pills.
RU-486 as Eagler just pointed out actually takes an already fertilized egg that's attached to the lining of the uterus and chemically changes the lining to make the egg and lining shed itself causing an abortion. From what I remember doctor's only prescribe it in the first trimester of pregnancy, but I could be wrong. The problem with prescribing it over the counter is that there has always been a followup appointment after taking the pills to make sure that the pregnancy has been sucessfully aborted. I can see making sure the morning after pill is available otc, but not RU-486.
Sorry, I was in college not too long ago and because of stupid behavior on my part I did a lot of research on these topics.
You know, now that I think about it, since birth control pills aren't otc because of complications and side affects, I don't think either of these should be as well. I think the first logical step in pregnancy/antipregnancy drugs would be to make a better birthcontrol pill with less side affects that could be approved for over the counter use....but I'm forgetting that men run the drug companies; a better birthcontrol pill is about as likely as a male birthcontrol pill.
I'll save that rant for another day.