I have a business card encased in plastic which hangs from each of my
camera bodies by the loop that the strap goes through. Amazing how
many people come up and ask who I work for. They just assume I'm a
professional doing business there. I tell them I'm a freelance
photographer, they don't realize how many different types of purposes
a freelance shooter could be shooting for......
But over and over I've found that tag gives me authority.
My photo vest helps as well.