According to CEO Michel Giasson, with whom I spoke via phone, NuCaptcha has a 95-percent success rate, which is a 10- to 20-percent improvement over other captcha services such as reCAPTCHA, which is used by Ticketmaster among other sites, and controls about 15 percent of the captcha market despite its 75-percent success rate. In addition, security expert Dr. Greg Mori, who has applied his research in object recognition to develop methods for breaking static captcha codes, endorsed NuCaptcha in an emailed release as “the most secure commercially available Captcha system available today.”

While the full-res version of NuCaptcha is powered by Flash, the technology does work across multiple platforms — including Apple’s iPad and iPhone — by downshifting to a 20-frame animated GIF. In addition, NuCaptcha is building out themes to match specific sites or their users, and customized themes will also be available as a premium offering sometime over the course of the next few months.

NuCaptcha is currently available as a free product for up to 25,000 captchas per month, aiming at smaller web sites and blogs. And there is now a WordPress plugin available for those who want to streamline the process; installation details are available here.

By making the text move, it now takes a little longer to process what you’re seeing. But typing in three letters — as opposed to two garbled words — is quite a bit simpler.

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Home page takeover ads – If you read The New York Times on the web, you must have viewed the BMW video ad that took up the entire home page two weeks ago (see the video here).  Touting BMW’s new line of “clean” diesel fuel cars, the ad made The New York Times’ home page show up as a black screen until the BMW spokesperson in the ad clicked on a light and then took you to the standard home page. The ad still played in the right-hand side of the page, however. It was a jarring interruption in my morning routine.

CAPTCHA ads – If you’re setting up a new account on a web site or purchasing something online, you’ve probably been prompted to fill out a CAPTCHA. It’s those blurry, stretched-out jumble of letters and numbers you’re forced to type into a box. Apparently, Microsoft is using its own form of CAPTCHA to market its products, such as the Xbox 360 video game console. Is Microsoft really that obvious, or is this supposed to be sort of tongue-in-cheek?

Pop-under ads – Though pop-unders are an old-school type of online ad, you can still run into them. Pop-unders catch you unexpectedly, because the ads are hidden underneath your browser. Once you’ve closed the browser, then you see the ads staring right back at you. If you visit The Washington Post’s web site, you’ve likely run into pop-under ads like this one to the left.

Sponsored blog posts – Last month, The New York Times wrote an article about bloggers being reviewed by the Federal Trade Commission for writing about products that companies sent to them for free. Though many bloggers argue that they don’t write about a product unless they truly like it, the FTC has drafted a set of guidelines that may require online media to comply with disclosure rules. Still, it’s often hard for me to tell whether bloggers genuinely likes a product they’re writing about. (Online video stars, including Fred, have been known to advertise certain products during their video clips.)

Hover ads – A different take on traditional pop-up advertisements, Hover ads are the ones that pop up and play a video after you accidentally scroll over them with your mouse. The ad’s purpose is to distract you and hide some of the site’s content for a few seconds. Hover ads are especially annoying because you can’t use a pop-up blocker to prevent them. I often watch the whole video before figuring out how to close the ad. Here’s an example of a hover ad for Project Runway that I found on TV.com

So readers, what type of online ads get under your skin? Over here at the GigaOM Network, Simon at WebWorkerDaily can’t stand the “punch the monkey” ads and Chris at NewTeeVee gets miffed over credit score ads. Share what you think in the comments section.

Photos courtesy of TechFlash and TV.com.

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NPR ran a story yesterday on Luis von Ahn, assistant professor of computer science at Carnegie Mellon University and one of the guys who helped develop the CAPTCHA technology. The short version: Efforts to digitize (really) old books and newspapers were being hampered by faded ink that confounded OCR software. The solution von Ahn came up with was to use the words that the software couldn’t recognize and insert them into these so-called reCAPTCHAs and use the power of human brains to decipher them. CAPTCHAs serve up two words, one is the security word, the other goes toward the book digitization effort. It sounded interesting, so I called von Ahn to find out more.

Here’s how it works. The New York Times is working to digitize all of its issues starting way back in 1851. It starts by scanning every single page as an image. That’s where reCAPTCHA comes in. It runs two optical character recognition (OCR) programs to turn all of those images of pages into text. Different OCR programs tend to make different mistakes. When the two programs disagree on a word, that word is plucked out and distributed among CAPTCHA security programs spread out across 45,000 web sites like Craigslist and TicketMaster.

Human beings then look at the words as part of the CAPTCHA security measure and do the deciphering by retyping what they think the mangled word is. Depending on the word, as little as two or three people agreeing on what it is is enough to figure it out. The word is then sent back to the New York Times to be reinserted into the text version of the image.

Initially, this project was part of Carnegie Mellon, but von Ahn said that they are spinning out reCAPTCHA as its own company. While The New York Times is paying to use the service, reCAPTCHA is also doing work free of charge for the Internet Archive’s project to digitize every book published before 1980.

But von Ahn is looking beyond just re-typing words as security measures. He says that his team has tried using images and having people type what they see. The problem, von Ahn says, is that people don’t spell very well, so even though the image is of a “cat” people could spell “kat” and not answer the question correctly. ReCAPTCHA is also expanding into audio, and using the audio version of CAPTCHAs to have people listen to and decipher words from garbled old recordings or closed captioning transcriptions.

The idea of taking a necessary evil like spam prevention and turning it into something useful is a good one. Who knew selling my old digital camera on Craigslist was actually an act of historical preservation?

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