We're going to try to allow comments on postings again: Several months ago, I posted a note about why we were disabling the ability to add comments to posts at Wi-Fi Networking News. The reasons were threefold: comment spam, often pornographic in nature, intended to improve search engine rankings of various sites; off-topics posts by people who didn't understand what the site was about; and posts that critiqued the site directly instead of the item commented on. While we like feedback, we've made it clear that the forum for that is through us to email (or on another blog, for that matter), not in our comments.
We're using Movable Type to run our blog, and the company behind it, Six Apart, has made available a system known as TypeKey which is a centralized, free registration system for commenting. The idea is that you sign up via TypeKey and verify your identify via email. It doesn't prove you're who you say you are, but they at least have a valid set of tracking information about you. With a TypeKey identity, you can post to our site.
I have trepidations about offloading this function to another party, however much I trust them and their infrastructure, but it's the best solution I've seen for allowing reasonable commentary. We'll experiment with this, and based on the kind of comments we get, see where we go from here.
(Please note: there's a small problem with the template that tells you that your comment is pending: it's slightly unreadable. I'll fix that as soon as I can, but it doesn't prevent posting comments.)