Outsourcing Commenting
There's a service called Disqus that provides hosted commenting for your blog or website.
My Ottawa Events site was recently hit by a deluge of spam - so much so that I had to disable commenting completely. I discovered Discus through Dave Winer's blog, and it seems like it's worth a shot, so I've enabled it on the Ottawa Events site.
I like the idea that I can sign up for an account with Disqus and that account works on any blog or site that uses them for commenting. These sorts of sites that provide hosted services to webmasters tend to get bought up by someone if they do a good job (as happened to FeedBurner, for example) so I'm not too worried about my comments disappearing, although that is a risk I take by letting someone else host them. Ottawa Events content is time sensitive, and the comments aren't valuable anymore once the event has passed, so if Disqus did disappear, I wouldn't lose a lot of valuable content.
There are two services that Disqus could be providing. One is simply managing commenting, which they're doing, but the other is filtering spam. I don't know how they do at that job, but if Disqus just becomes another spam target, their value disappears. Hopefully they're well aware of that.