Last night Vancouver-based NuCaptcha took the wraps off their new take on an old problem: the captcha. NuCaptcha uses video (and often an ad), moving words, and color to make a captcha that should be difficult to impossible for computers to solve. Could this be the next way to defeat spammers and provide ad revenue for site owners?

We've all seen them filling out forms online. Do some math, look at semi garbled characters, choose a picture, something to prove that, yes, I am a human, before a form can be submitted. The goal is to prevent bots and spammers from submitting comments or gaining access to sites, while letting people in. The general flaw in captcha systems has been that eventually either clever geeks find ways to scrape and access captchas through better and better image processing or cheap labor can be employed to have real humans fill in captchas all day to gain access to sites, etc.

Read More:
http://thenextweb.com/ca/2010/10/25/nucaptcha-combines-video-and-ads-for-new-captcha-solution/