Newly VC funded Automattic has released a version of their Akismet anti-spam package for Movable Type:

It still isn’t 100% to where we want it, as interactions with MT’s built-in spam filters and options can negate Akismet’s effectiveness, but we feel it’s now to a point where it can provide a much better protection than MT users are getting currently.

Problogger’s Aaron Brazell appears to think highly of Akismet:

When I installed Akismet at Technosailor, I was truly amazed at how well it handled spam. Literally, I went to maybe one comment a month that needed to be moderated. That was with no comment moderation enabled (save Akismet’s), and only Akismet installed as an anti-spam plugin. I was truly amazed.

All of our WordPress sites that are upgraded to WordPress 2.0 are using Akismet. I installed Akismet for MT last night and have already noticed a reduction in spam comments – we’re hoping that this trend continues.