How to stop bots from posting?

[bob weaver]

There's one product that gets about 10 new reviews every day, all from an anonymous, unregistered user, and all the reviews say the same thing. Is this a bot doing this? The IP addresses are all different. You can see what I'm talking about at this page:

http://fireworksland.com/ultimate/sh...p?product=6311

Is there any way to stop a bot from adding reviews, while still allowing unregistered guests to add reviews?

[Chuck S]

If the ip address is different from all there is no way to stop them that i see as you allow anonymous posting which means anyone can post.

[TheSonic]

I have the same problem. My way: Moderate unregistered reviews. I delete alle the Spam and it never befores shows to users.

Any CAPACHA-Security would be great

[Chuck S]

captcha is a nice idea and easy to do