Simon,
While I'm not sure what you mean by saying that most philosophers working in ethics think that morality is something "out there" I suspect that on a suitable clarification of "out there" it will turn out that lots of constructivists, quasi-realists, and anti-realists of various varieties will not think that morality is out there.
My intended next OB post will, in passing, distinguish between moral judgments and factual beliefs. Several times before, this has sparked a debate about the nature of morality. (E.g., Believing in Todd.) Such debates often repeat themselves, reinvent the wheel each time, start all over from previous arguments. To avoid this, I suggest consolidating the debate. Whenever someone feels tempted to start a debate about the nature of morality in the comments thread of another post, the comment should be made to this post, instead, with an appropriate link to the article commented upon. Otherwise it does tend to take over discussions like kudzu. (This isn't the first blog/list where I've seen it happen.)
I'll start the ball rolling with ten points to ponder about the nature of morality...