stonecolddevin has asked for the wisdom of the Perl Monks concerning the following question:

Hey monks,

I'm trying to figure out how to create a system where the user must type in a phrase or somesuch from an image that's displayed on the page as a form of verification to prevent spam, autosignups, etc. Yahoo! and Google's Blogger do this (A PHP tutorial here, and an example here (near the bottom of the page)).

I know merlyn has an article on this on his website, but I can't seem to find it.

I also know it's going to involve GD::*, or Image::Magick (or something along those lines), a random string/word generator, and some hidden form values. Beyond that, I'm not sure.

Any ideas?