Eric Meyer: WP-Gatekeeper: A more accessible CAPTCHA solution to prevent comment Spam in WordPress. Interesting solution that has been tried before and has had mixed reviews from users. [EDIT] Interesting twist I did not quite catch at first glance My goal was to create a system … rotates between as many challenges as one cares to set up. It could be just one challenge, or a set of 100. So a blog could ask for the blogname, the author’s name and the day of the week, for example.