jcatcw writes "Steven J. Vaughan-Nichols reports that CAPTCHA cracking isn't that difficult these days. It has even become a business. For example, DeCaptcher.com will solve CAPTCHAs for your spamming needs at a rate of $2 per 1,000 successfully cracked CAPTCHAs. In response, newer systems are in development. Both Carnegie Mellon and Penn State (is there something about the water in PA?) are working on image-based systems. ESP-PIX and SQ-PIX both require the viewer to interpret pictures. Imagination CAPTCHA from Penn has the user find the center of an image. The idea is that humans are better at image recognition that computers, but humans can legitimately disagree on their interpretations and some humans are color blind. Problems remain. For now, sites would be well advised to look at reCAPTCHA — the system that works with Google Books and the Internet Archive to digitize printed texts — which comes with a wide variety of application and programming plug-ins and an open API."