The folks over at SixApart have been looking at the performance of MovableType and have some recomendations for those of you that upgrade to the latest version 3.34. Those that have their own servers or that are on hosting accounts can install FastCGI to get as much as a 15x increase in performance in their existing installations.
I will be adding the FastCGI support here, and we will see how much it helps when the site is under a comment spam attack. [www.sixapart.com]