WordPress MU

I have the default options set that makes all comments go into moderation, but some users choose to let everything pass.

The problem is that some posts are having over 500 spam comments and growing everyday. What can I do to prevent spam comments getting there?

Is anyone using http://tantannoodles.com/toolkit/spam-filter/ with mu1.3? I think something like this would work for me. Other spam solutions I have installed is the signup question, and CAPTCHA for comments. All I am missing now is this option.

I use SK2 (for the moment) for comments, as well as a custom captcha. It's pretty darn effective.

SK2 as well here. I;ve got it turned off right now because of an unrelated technical issue, and lemme tell you, the difference is *amazing*

On a related tangent, I have found that the internal Wordpress spam-stopping stuff (blakclist, etc..) would be *so* useful in MU if that area was global.