I've always been a trifle annoyed by being asked what I'm going to do with philosophy (or a philosophy degree, whatever). I don't doubt that some people ask it sincerely - genuinely curious about the usefulness of studying philosophy - but I seriously doubt that most people do. Most often it seems a not too subtle sort of power play - "Ah!" they seem to be saying, "You have this degree in something and you're clearly thinking it's important, but watch me as I cleverly deflate your sense of self importance by asking you this seemingly innocent but really quite clever question!"
You know, it's like Socrates but for businessmen.
You really have to read the whole post - the author has earned my undying respect for this one. (In fact, his is probably the most consistently amusing philosophy blog I've come across. Highly recommended.)
Seriously though, what do you answer when someone asks you That Damn Question? [I do like Dr. Pretorius' suggestion, but I'm not convinced my uncle would take it very well ;)]