My personal opinion is that if the person using the word is a member of that group, then they get to decide whether or not it's appropriate to use it. Especially if the group has been historically oppressed or marginalized. Tim Wise gave a good statement about a similar word below. I will never use the T-word, but I would never begrudge RuPaul her right to use it.
However, as an overweight Canadian female of Irish descent, I reserve the right to call myself a "fat Canuck Mick bitch" whenever it seems appropriate.
