[jonrob]

One site that I think deals with this problem quite well is Metafilter. The comments are full of thoughtful and well reasoned discussions between the readers. Sure, there are problems: sometimes someone posts something that's mean spirited, or there's a few too many one liners in the comments thread, but, on the whole, these problems are rare.

In fact, the quality of the comments are so high that there's even an Ask Metafilter sub-section, where readers post, often very personal, questions and do so without fear of the kind of reaction they'll get.

What's most interesting about the Metafilter model is that there's no up- or down-voting, only favouriting.

So how do they ensure the quality of the comments? Well, to become a member you have to pay a one off $5 charge. It's not much, so almost everyone can afford it, but it seems to be enough to discourage drive-by comments or anyone who's not serious about contributing respectfully and substantively.

There's also the possibility for posts and comments to be deleted, and for an account to be banned completely if someone fails to follow the guidelines. I don't think this happens often.

http://www.metafilter.com/about.mefi http://www.metafilter.com/guidelines.mefi http://www.metafilter.com/newuser.mefi

[obtu]

As a MeFite: even the favouriting isn't necessary. It can polarise discussions and turn them into a back and forth where each side tries to get higher scores. I'm hiding those, and idly wish they hadn't been introduced.