Niteo

Spider Blocker blocks most common bots that consume bandwidth and slow down your blog. 
It accomplishes this by using .htaccess file to minimize impact on your website. It’s hidden from external scanners.
Spider Blocker is specifically designed for Apache servers with mod_rewrite enabled, allowing you to effortlessly safeguard your website from the most prevalent bots that hamper performance and drain resources.
<h4>Plugin Features</h4>
<ul>
<li>Block Unlimited bots from viewing your site</li>
<li>Easy Export/Import rules (comes with most common list of bots)</li>
<li>Zero Footprint</li>
</ul>

Spider Blocker

Does what it promises to do. No more bad bots to my WP blog :)

Perfect!

SpiderBlocker will block most common bots that consume bandwidth and slow down your blog.

pedjas

Displays Apache and PHP version in footer of admin section for easy access.
These information are usually needed if reporting bugs or checking hosting service configuration. WordPress displays only it’s own version which is not enough.
Plugin is very simple and uses almost no resources. After all, it just displays version information.

Spider Blocker vs Show Apache and PHP version