I think the killer app for Mechanical Turk is already out there. Think about it: what’s very simple for a human, very hard for a computer, shows up everywhere and acts as a gatekeeper from potentially greater value?

That’s right: those little “verify you’re a human” image boxes that make you transcribe a series of bendy, obscured letters and numbers in order to leave a Blogger comment, or get an LJ account or a GMail address. (Less awkwardly, more annoyingly, they’re called CAPTCHAs.) Yoz Grahame pointed out like a year ago that these are a solved problem: you just go to a CAPTCHA page, grab the image, and put it in front of porn on one of your other sites. Step three: profit!

The only problem with that scenario is that, well, there are ways to get porn without all that tiresome thinking, and most porn-seekers will take them over your time-consuming verification step. It’s easier to type BRITTNAY SPEER NUDE into Google Image Search than it is to decipher Ty$23YiD.

But if MT’s model works (and I’m not saying it does; right now only Amazon uses it, and you’d have to work hard and boringly to make five bucks an hour), and if it gets sufficiently popular that the site’s admins won’t notice spammers slipping CAPTCHAS in, this could be a viable crack. Sign up for an account, pay Random Human two cents to verify it, and spam, spam away. It’s okay, say the servers you’re using to link your herbal V1agra incest mortgage. I know that’s not a bot!

CAPTCHAs are the least bad solution to bot-signups out there right now, but I hope the tech startups that are built around providing that kind of authentication don’t get comfortable. They’ve never been more than a stopgap.