<p>WP Spam Hitman is based on set of rules and concept of hitpoint. With right set of rules and hitpoint level you can eliminate most or even all of the spam on you blog.<br />
It works in 3 modes – Delete, Moderation, Spam and is quite customizable.<br />
It allows to set unlimited set of rules – both – simple words and regular expression patterns. It’s simple but powerfull tool for fighting with spam.</p>
<h3>Changes</h3>
<h4>0.7</h4>
<ul>
<li>added – Message ‘%tags%’ – you can place information from comment in your message for spammers</li>
<li>fixed – bug – now you can change message for spammers</li>
<li>change – default message for spammers changed to less offensive</li>
</ul>
<h4>0.6</h4>
<ul>
<li>fixed – bug with displaying message on modes moderation/spam</li>
<li>added – version number displayed on the right of plugin name in options</li>
<li>added – version checker – it checks if you have the newest version available and if not – tells you about it providing link to the newest one</li>
</ul>
<h4>0.5</h4>
<p>First public release.</p>


WP-Spam-Hitman

WP Spam Hitman allows you to fight with spam using set of patterns and hitpoints. It also allows you to decide what's going to happen to the spam

Automattic

Donncha O Caoimh (a11n)

<p>This plugin adds a stylesheet or image to your blog’s html source code. When a browser loads that stylesheet or image a cookie is dropped. If that user then leaves a comment the cookie is checked. If it doesn’t exist the comment is marked as spam.<br />
The plugin can also check how long it took a user to enter a comment. If it’s too fast it’s probably a spam bot. How fast can a legitimate user enter their name, email, web address and enter a well thought out comment?</p>
<p>For the adventurous, add these lines to your .htaccess and it will block spam attempts before they ever get to WordPress. Replace the Xs with the cookie that was set in your browser after viewing your blog. You can also find the cookie value by examining the page source code and looking for “css.php?k=XXXXXXXXXXXXXXXXXXX”. Make sure the lines go above the standard WordPress rules.</p>
<pre><code>    RewriteCond %{HTTP_COOKIE} !^.*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.*$
    RewriteRule ^wp-comments-post.php - [F,L]
</code></pre>
<p>If you use WordPress MU, replace wp-comments-post.php above with wp-signup.php to block spam signups.</p>
<pre><code>    RewriteCond %{HTTP_COOKIE} !^.*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.*$
    RewriteRule ^wp-signup.php - [F,L]
</code></pre>


Cookies for Comments

If you don't use any other spam filter plugins, then you can rely on this to stop spam comments for sure!

Must have, if you don't use any other spam filters!

I'd been getting a dozen spams a day on two of my sites. We installed "Stop Spam Comments" on one and "Cookies for Comments" on the other. Both worked perfectly. No more spam. Thanks!



very easy and no more spam!

Sets a cookie on a random URL that is then checked when a comment is posted. If the cookie is missing the comment is marked as spam.

WP-Spam-Hitman vs Cookies for Comments