It's strange that almost 900 posts into this physics blog, I would have a post that would ask that question. :)
Well, I wasn't the one asking it, but this article did. It is a piece written by Ian Cuthbert of the Institute of Physics in UK. I think this is a simplified answer to that question. The article deals mainly on the typical educational path that a student in the UK would take to become a physicist. So it is more of a description on how to be a physicist, rather than "what is physics".
Still, it is useful for those considering this career, if you're in the United Kingdom.