Originally Posted by StuartD

I built a simple guestbook script and recently it's been getting hit pretty hard by poker spammers with all kinds of various crap... over 200 submissions in 2 days.

The question is, what's a good way to prevent that without limiting genuine guestbook submissions?

And no, I don't want to go with image verification because it's just a guestbook for every day people. I don't want to make it a chore for them.

I checked the referrer and it is coming from my own site, so it's not an off the site submission. Someone must have built a spammer that submits the actual form on the page.. so I can't just check for the referrer