Markus Bopp of Crosstec created a Mollom plugin for Joomla. The plugin is code named Jollom and can be customized to protect any form.

Mollom is a web service that helps you identify content quality and, more importantly, helps you stop comment and contact form spam.

Top 5 benefits

• Kills comment and contact-form spam
• Overall content quality improved
• Burden of site moderation reduced
• Faster community growth
• It's FREE!

Top 5 features

• Accurate spam filtering
• Eliminate your moderation queue
• Detailed statistics
• Image and audio CAPTCHA challenges
• High-availability infrastructure

Link | Mollom.com - Jollom