Can't help you with the southern snakes, but here in PA I'm always on the look out for the Pennsylvania Hoop Snake. Very rare and even more deadly.

http://ezinearticles.com/?The-Dreade...ake&id=1030006

http://www.americanfolklore.net/folktales/pa.html

http://www.museumofhoaxes.com/hoax/a...comments/4347/