Another technique is implementing a honeypot field which is hidden with javascript. It's supposed to be empty, but bots often fill them out too. I recommend t

Another technique is implementing a honeypot field which is hidden with javascript. It's supposed to be empty, but bots often fill them out too. I recommend to evaluate Akismet[1], the blog spam detection api from Automattic. It worked very well for me. [1] http://akismet.com/ http://akismet.com/