Defensio is a spam filtering web service that you can use to protect your blog or web application from comment spam.
Here are some shorties from their site:

• Stellar accuracy, thanks to an adaptive, personalized filtering algorithm
• Ridiculously easy spam management
• RSS feeds of your comments and spam
• Detailed statistics for complete transparency

It point itself as a replacement for Akismet, so if there is a choice, ColdFusion Community should have access to it as well.

This being told i am glad to present ColdFusion implementation of Defensio API

It have all existing API functions (as by today):

• validate-key - verifies that the key is valid for the owner calling the service
• announce-article - invoked upon the publication of an article to announce its existence
• audit-comment - check if a comment is spam or not, and also measure its "spaminess", i.e. its relative likelihood of being spam
• report-false-negatives - indicate to the filter that comments originally tagged as "ham" (i.e. legitimate) were in fact spam
• report-false-positives - indicate to the filter that comments originally tagged as spam were in fact "ham" (i.e. legitimate comments)
• get-stats - returns basic statistics regarding the performance of Defensio since activation

THIS is the download link to defensio.cfc