Kent Brewster has come up with a novel solution for the inaccessible image-based captchas. Captchas are those images of obscured text to keep robots from spamming web sites. They’re a royal pain for those with visual disabilities.
Kent has solved this with a Web 2.0/social bookmarking bent. His RSS CAPTCHA Prototype asks you to visit a blog from his blogroll and copy the latest headline. You then paste the title into the form and if it matches, a cookie is set to say that you’re a good guy and can comment with ease in the future.
There are some inherent problems with this approach. Your visitor has to leave your page, go to another, copy the text, come back, and then paste it into your form. All of this for the sake of posting a comment. However, tabbed browsing makes this much easier. Internet savvy audiences could handle this and possibly discover some new blogs.
For WordPress users, the best approach is still the amazing Akismet spam filter. Stop the spam, not the commenter is the concept behind Akismet.