ThemeShock

Custom 404, helps you customize your 404. 
From the dashboard options you’re able to modify the background, the image and the fonts color and style.
This page will show users the last post on your site, so that they may choose to follow one of this instead of leaving your page.
<h3>Features</h3>
<ul>
<li>Customizable background</li>
<li>Several Patterns</li>
<li>Multiple fonts</li>
<li>24 additional images.</li>
<li>5 Different languages</li>
</ul>

Custom 404 Error Page: Unilimited designs and colors

Custom 404, creates a 404 page that is set to the default one of your WordPress installation.
This page is fully customizable from the dashboard.

Johnnie

<ul>
<li>NOTE: Please read installation instructions. WP Maximum Execution Time Exceeded plugin requires that you complete the website backup process. </li>
</ul>
WP Maximum Execution Time Exceeded is a very simple and effective plugin. If you’re receiving the message “Maximum execution time of 30 seconds exceeded” or “Maximum execution time of 60 seconds exceeded,” this plugin is for you.
A time out means that the process you would like to complete is simply taking longer that the program will allow. The clock needs to be set for a longer time period. To address the problem of maximum execution time exceeded, WordPress Codex offers two solutions. One, edit the .htaccess file and two, edit the php.ini file. This plugin uses the first of the two suggestions. WP Maximum Execution Time Exceeded will add and delete the necessary code to the .htaccess file.
When WP Maximum Execution Time Exceeded is activated after installation, the plugin will write to the .htaccess file. To delete the code, simply deactivate the plugin. There is no administration page.
You do not have to delete the files to remove the code. When you’re ready to rewrite the code to the .htaccess file, simply activate it. This allows you to test your process with a longer timeout. It’s that simple! And of course, this plugin creates no load on your website. It’s so light weight; you’ll never know it’s there.
<ul>
<li>NOTE: All feedback and suggestions are welcome. I am constantly looking for ways to improve and upgrade WP Maximum Execution Time Exceeded. Please contact me with your ideas for a better plugin.</li>
</ul>

WP Maximum Execution Time Exceeded

I know enough to edit .htaccess files but couldn't manage to extend the execution time without creating an Error 500.

One click and this did the job...and taught me how to do it manually in future ;o)

Perfect

Did you receive a message, "Maximum execution time of 30 seconds exceeded?" Not anymore. Just Plug'n-Play. It's that easy!

Custom 404 Error Page: Unilimited designs and colors vs WP Maximum Execution Time Exceeded