I was raised to believe that asking someone "what do you do" is a politer variation of "where do you work", itself a pry into their income level, and the proper response is to describe your hobbies or goals.
The real answer here is you probably wouldn't want to have a conversation with me anyway.
I intend the question and respond to it as an inquiry into what kind of work you enjoy doing and spend your day at. Like are you a teacher, rocket scientist, software engineer doing Ruby for a startup, etc. I'd rather talk to people about what they're interested in doing than some income pissing contest.