WordPress MU

So, I've been doing a lot of thinking about comment spam - yet again - and trying to find a solution that isn't SK2 or Akismet... reason being Akismet is too expensive for any enterprise use by a non-corp (or someone like me who's completely povo) and SK2 seems to take over my installation whenever I move towards installing it... and it's not GPL either.

So I was wondering whether any WPMU hosts had expwerience with these alternative spam blocking plugins and whether people had any tips for other ones:

Challenge - I really like this one as a straightforward comments spam stopper but I can't get it to still show on themes which remember the commentator ID - v. frustrating.

Trackback validator - Looks promising (as does trackback validation from here too.)

Comments policy - A nice blocker measure and useful add on for institutional / company sites.

Any of the captcha solutions.

A pretty irksome plugin failure with 1.0 has been the auto-close trackback and comments plugins both causing sql errors :( If anyone has a working version of knows of an alternative I'd also be greateful!

Over and out.... James

Since I initially had a lot of problems with installing SK2, i searched this a bit in the past, and couldn't find anything suitable.
None of the other scripts available are either maintained, or come anywhere near SK2's efficiency. Of course you can force a challenge or captcha, but that's at the cost of a lot of annoyance for users. The good thing with SK2 is that you'll only be challenged if your score based on other parameters leaves any doubt to whether you are spamming or not.
Also, it would really be sad on a wpmu install not to benefit from a global blacklist system, leveraging on the comment spam reported by some users to prevent others from getting it, kindof like akismet does, but locally.
Anyway since I'm a bit off-topic answering that SK2 is the solution to a question that ruled it out i'll stop now, but i'm really curious to know how it "took over" your installation, since mine is breezing and installing it didn't have any notable impact on perfs...

I am an idiot.

Just found the WPMU version of SK2 over at wpmu dev and installed that... works like a treat :)

Sorry!