From an interview by Kicker Studio of London designer Crispin Jones, where he says that the broad definition of design is perhaps not so bad.
On one level design is horribly inarticulate word - it has no real meaning nor way of encompassing all the things that are classed as "design". This weakness however means that the discipline is kind of without boundaries. I think design allows you to engage with the contemporary world and engage in shaping the world: we're living in a golden age of products/services as technology matures and people integrate it into their lives.
You may have picked up on this by reading kottke.org over the years, but I think that designers, architects, entrepreneurs, filmmakers, writers, scientists, et al. are all engaged in doing the same kind of thing, more or less, and that working "without boundaries" and borrowing the best aspects of many disciplines is one of the keys to maximizing your creative potential. (thx matt)