Sparked by the desire to run my blog in FarCry, and being inundated with blog spam, I've cobbled together a nifty little plugin for FarCry called modCaptcha that uses LylaCaptcha to generate a captcha formtool.
Built by Peter J. Farrell et al, LylaCaptcha is a Captcha created for implementation with ColdFusion. A Captcha is a type of challenge-response test used to determine whether or not a user is human. A common type of Captcha requires the user to enter the correct string of characters that have been distorted in an image. A Captcha can also be an response to a question that most people should be able to answer. This library is released under the Apache 2.0 license at http://lyla.maestropublishing.com/
The plugin is real easy to install, and works with FarCry's awesome formtool system to build a LylaCaptcha image for your form. The formtool is used just the same as any of the formtools you may be familiar with in v4.0 – just create a boolean property and set the fttype="lylacaptcha". The captcha should be automatically created and managed.
I've updated the FarCry Plugin Portal with installation instructions; modCaptcha Documentation
As it's a little personal project, I decided to try hosting my modCaptcha code at Google Code. So far so good. modCaptcha also released under Apache 2.0.