[Harvey]

Of course it depends on the size and type of forum. For a site of this size, I don't think moderators are necessary. When you start getting reported posts coming in every few hours, that's when moderators may be handy. You can't be online always, so it's always handy to have someone on the other side of the world moderating when you're asleep. That way, you don't wake up to a million unread reports! :p