From Jimbojw.com

Recently I've been getting spammed on the comments to GTalk Emoticons - probably because this is the #1 traffic generator for my site.

So, here's a new version of the ArticleComments Extension (download) that has slightly better spam detection. Still rudimentary, but it should catch more spam now.

I've also abstracted out the spam checking out of the core code by adding a new hook called "ArticleCommentsSpamCheck". The extension provides a default implementation that hooks into this.

From here out, development of any additional spam filters should be easy without changes to the extension's core code. Maybe an Akismet wrapper would help.