jammycakes

This plugin rejects outright any comments that contain either (a) BBCode 
[url=…] tags or (b) more than a predefined number of hyperlinks. As comments 
of this nature are almost exclusively spam, this should cut down drastically on 
the amount of detritus that Akismet has to deal with, making it easier to check 
for false positives in your spam queue.
<h3>Configuration</h3>
The default settings enforce a limit of two hyperlinks per comment. 
To change this, edit the number in the line just below the copyright notice 
which says:
<pre><code>define('MAX_HYPERLINKS', 2);
</code></pre>
If you set it to zero, it will not allow any hyperlinks. To allow unlimited 
hyperlinks and only block BBCode, comment out this line.
<h3>Redistribution</h3>
Copyright (c) 2007 James McKay 
http://www.jamesmckay.net/
Permission is hereby granted, free of charge, to any person obtaining a copy 
of this software and associated documentation files (the “Software”), to deal 
in the Software without restriction, including without limitation the rights 
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
copies of the Software, and to permit persons to whom the Software is 
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in 
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
SOFTWARE.
<h3>Reporting bugs</h3>
When reporting bugs, please provide me with the following information:
<ol>
<li>Which version of Comment Timeout you are using;</li>
<li>Which version of WordPress you are using;</li>
<li>The URL of your blog;</li>
<li>Which platform (Windows/IIS/PHP or Linux/Apache/MySQL/PHP) your server 
is running, and which versions of Apache and PHP you are using, if you 
know them;</li>
<li>The steps that need to be taken to reproduce the bug;</li>
<li>If possible, any relevant information on other plugins or configuration 
options that you may think appropriate.</li>
</ol>
See the following blog entry for further guidance on troubleshooting and 
reporting problems:
http://www.jamesmckay.net/2007/04/how-to-report-issues-with-wordpress-plugins/
<h3>For more information</h3>
For more information, please visit the plugin’s home page:
http://www.jamesmckay.net/code/link-limits/
The Mercurial repository and issue tracker for this plugin are at:
http://bitbucket.org/jammycakes/link-limits/

Link Limits

Rejects comments that contain BBCode or too many hyperlinks.

MikesPickz

MP Spam Be Gone is the simplest, most effective Spam blocker without difficult CAPTCHA responses needed by the user. This plugin was inspired by some of the best Anti-Spam plugins available on WordPress.
Inspirations: 
Spam Free WordPress by Todd Lahman, LLC 
Growmap Anti Spambot Plugin by Andy Bailey 
Simple Trackback Validation with Topsy Blocker by Tobias Koelligan
This plugin has aspects from all of the above mentioned plugins to form the most complete and dead simple Anti Spam plugin on WordPress. This plugin doesn’t write anything to your database while preventing comment spam and trackback spam.
From Growmap Anti Spambot Plugin, I used the concept of having a checkbox display to the user in order to prevent automated Spam. To me this is the best way (and least intrusive) to completely prevent automated spam from ever even being written to the database in the spam que. It is physically impossible to get a false positive, since you either checked the button or not. The flaw with this plugin is that it does not work with Javascript disabled.
To combat that flaw, I use the copy and paste password fields from the Spam Free WordPress plugin. These fields are in a <code><noscript></code> tag, and only appear if Javascript is disabled. Unlike, the Spam Free WordPress plugin, these passwords are generated on the fly and never stored in the database.
These plugins primarily stop comment spam. In order to stop trackback spam, I added the IP address check, URL check, and Topsy check functions from Simple Trackback Validation with Topsy Blocker. If a trackback is identified as spam because of the IP address or Topsy, it is deleted and never written to the database. If a trackback is identified as spam because of the URL, it is marked as spam and sent to the Spam que. The reason that these are not automatically deleted, is because it is possible that the referring page is using a shortlink and therefore the full URL would not appear on the page in the first place.
When combined, this plugin will stop all automated spam and trackbacks.
It is intended to replace the above plugins.
You can’t find a plugin simpler than this – set it and forget it. No options = no modifications to the database.

MP Spam Be Gone

MP Spam Be Gone is the simplest, most effective Spam blocker.

Link Limits vs MP Spam Be Gone