Can't read your way past the humans-only gateway on that Web site? NuCaptcha has a filter that's easier for you, harder for robots.
Google's massive book-scanning project could produce more accurate results with ReCaptcha, a twist on the captcha-style log-in screens found on many Web sites.
Those online vision tests aren't just a way to tell human from bot. They're also helping rejuvenate old books and newspapers.
Turn annoyances into good with ReCaptcha, the distributed captcha project.