What a great idea. It's always a good thing to talk to your sex partners. But what if you get some infection? It's embarrasing and hard to bring up the subject or even tell them that you "got" something.
A program here in San Francisco, lets you send an annonymous email to all the people you've had sex with. With this day and age, most everyone is meeting people online, so this is a great way to let all your partners know that they might have been exposed to something.
The best part of it, is that it can be done annonymously, so no embarrasement. You can go through your phone book, or history and send an ecard to notify them that they may have been exposed to something. It's up to that person to go see their doctor or clinic.