I’ve been getting shelled with comment spam recently, so I just added a CAPTCHA plugin (called reCAPTCHA) that will hopefully weed out all of the annoying links to bad porn sites, viagra offers and online gambling sites showing up in my mailbox. Readers have been saved from this annoyance because I moderate all of my new commenters, but it’s starting to wear on me.  Sadly, this will also mean no more ‘cool’ comment spam, but that’s life.

CAPTCHA stands for “Completely Automated Public Turing Test to tell Computers and Humans Apart,” and is basically a way to weed out bots by using a simple ‘reverse’ Turing test that sets up a challege/response that a computer will most likely fail and a human will most likely pass. It’s a very practical application of Artificial Intelligence techniques (although applied for the opposite reason – to see how stupid a computer is, not how smart it is).

This particular implementation is cool because, while it does require an additional step for users who want to enter comments on my blog (aka, Jeannie), each successful ‘pass’ of a CAPTCHA on my site will help advance the cause of digitizing books. Cool, right?