In my profile, I say "[b]ecause LiveJournal is used by spammers (and I don't have any fancy WordPress plug-ins to screen spam), anonymous comments are screened... but still allowed. Please feel free to comment!" Turns out I was on the money, and I get quite a bit of spam here, almost all of which has been anonymous comments.
I've had a few anonymous comments that made me glad that anonymous comments aren't outright banned, but the vast majority have also made me happy I screen them. So let me reiterate: anonymous comments that are more than just search engine keywords and links to spam are completely welcome, and I'll try to unscreen them and make them visible as quickly as I can. If you have an LJ account or OpenID, you'll get through quicker, but I try to be responsive about anonymous comments too.
