How can I stop spam comments?

Thx

I keep up with my site. But when i allow guests to post, then every 5 seconds there's a spam comment. I turned off guest posting now.

I'll read the links you gave me. thanks

turn off guest posting all together.. if it's worth commenting on, it's worth registering.

you can run background checks on all of your members at http://www.stopforumspam.com ..

you know, if you have thousands of spam posts, you're not keeping up with your site.. you'll need to work on that more than anything else.

you might wanna read THIS too. : http://www.codeproject.com/KB/web-sec...ptcha.aspx

I deleted all the spam comments from the database, but how can I stop a comment with link or certain words from being posted?

And once more advice - you must block all comments with links. (and remove they from DB if you need that)

Thank you for your answers. I just figured out today that this was happening as I had over 70,000 comments and only a couple of hundreds were not spam. It was slowing down my website as well.

What do you mean by a "spam word list" ? Where would I put that? How would I use that to stop the comments from being added when they have certain words?

You can block 99% of the spam with a good "spam word list".
Look at my Guestbook infusion ;)

Changes in the comments-form maybe save you :)
But this changes - must be only at your site... Exclusive!

not really. maybe with some new captchas and a spam word list. that could work.

But the best thing you can do is only allow members to comment.