Defeating blog comment spam – an experiment

I’m getting a lot of spam comments on here, even with Akismet and other spam filters enabled. I’m going to try a little experimentt for a week – if you want to comment, you’ll need either an OpenID or a login with Vox, Livejournal or Typepad.
Also, once you post a good comment on my blog (or at least a non-spam comment), I’ll manually add you to the list of trusted commenters, and your post will appear instantly.
Anyway, if you’ve left a comment in the past, please try and leave a comment on this post, so I can see if it affects things much.