While doing a wee bit of research for a class (I was reading up on the Hessian town of "Schlangenbad"="snake-bath/spa") I happened upon this intriguing bit of trivia -the Rod of Asclepiuus is an ancient symbol associated with medicine and healing. It depicts a single serpent wrapped around a rod/staff. But there is also the caduceus, which is the staff that Hermes carried and is usually depicted as entwined by two serpents, sometimes with wings at the top--as you can see in the above picture. For reasons too varied to get into here the cadeuceum is sometimes used as the symbol of medicine --which is what is going on here since I took this shot right next to a dentist's office in the little strip mall on the way to my apartment.
You can read up on the whole controversy here.