I think the difference between Geek and Nerd isn't so much degrees of separation, but approach. Maybe it's just the association with the movie, "Revenge of the Nerds" but to me nerd is a way of life, whereas geek is a passionate pursuit. A photo-nerd wears their Domke vest 24/7 and worships at the alter of Fred Picker (justifiably).
A photo geek might engage in a debate between zoom and fixed lens, but would rather be in the soup.
To me a nerd is almost more about identity and geek is all about passion. A nerd talks about taking pictures, a geek takes pictures.
Now I'm not saying that one is better than the other, or that anyone who's chosen to be identified as a "photo-nerd" in this poll is a nerd as I've described, I'm just saying that this is my distinction between the two labels.
The one thing the nerd and the geek have in common though, is that if either is a "Canon-guy/gal" or a "Nikon-guy/gal" good luck in persuading them otherwise.