No, I haven't. I think it would be pretty hard to find someone through the dis. I did find someone that went to my high school, well, not her, but her dh is a DIS'er. He noticed a post I made about living near Chattanooga one time.
Classmates.com might be a place to look if you went to school with the person-maybe they registered there. Or going through google and typing in their name, or going to Yahoo people search might help. Or if you have icq or some other kind of service like it, you might could do a people search there too.