[peoplerock]

What do you mean by "simple math captchas"... where the distorted characters display something like "2 + 3 =" - and I'm supposed to type 5 or five?

Or are you simply using a simple math question (un-captcha'd)?

I've been experimenting with my own db of questions that can be answered with a word - including simple arithmetic and simple reasoning such as "Which is warmer? Hot or cold?" - and finding almost no spammer cares enough about my sites to develop a decoding table for comment submission [that would of course change if I were Amazon, etc.]

All of this is moot, of course, if some spammer were to care enough about auto-registering/emailing my site to get porn-visitors to solve the questions/captchas in order to "see more".

[RiderOfGiraffes]

Example: "In digits, what is 8 plus five?"

The formmail script then checks for the right answer.