> which meant that every new account

> would need to be touched by, at least,

> one human being.

No, it means that every new account would need to be touched by a human with a completely functional pair of eyes and a browser that displays images. Not exactly the same. You are thinking of a Turing test. Image recoginition always fails the Turing test.

There are two Movable Type plugins (although one goes a bit further) that utilize this technology although I will leave searching for them up to the user since I find it to be a particularly onerous solution which cuts out an already discriminated against segment of our society.

> That technique, for what it's worth, is called

> CAPTCHA, and was developed at CMU.

It was developed in parallel at i-drive and first released on the net in the summer of 2000. How do I know? Because I was Product Manager for the group that developed it.

Great solution at the time. Terrible solution in retrospect.

> BTW, I'm pretty sure that Yahoo was using the

> "type the phrase in this fuzzy GIF into this field"

> method long before Paypal, but I could be wrong.

Actually, the order was i-drive, Hotmail and then Paypal. I don't know how long after Yahoo debuted theirs...

> I suppose we should be grateful that nobody's

> yet tried to patent it.

i-drive did try, but then flamed out before (if I remember) the patent could be filed.

Anyway, comment spam is far different than email spam. Install MT-Blacklist, and you will understand why. That is, unless you aren't getting any spam...