Janis Elsts

This plugin will add a “Settings” link to every active plugin listed on the “Plugins” page (right next to the “Deactivate” and “Edit” links). This makes it easy to acccess plugin configuration without hunting through the entire dashboard menu.
The plugin finds the right admin page by automatically scanning through the WordPress menu structure to detect configuration-related plugin pages. Lab trials shown success rate of over 95%.
Additional notes :
<ul>
<li>Quick Configuration Links will automatically skip plugins that add their own custom link(s) to their “Plugins” page listing.</li>
<li>If a plugin has only one menu entry, the “Settings” link will always point to that page – even it has nothing to do with configuration. This is by design.</li>
</ul>

Quick Configuration Links

Automagically adds a "Settings" link to every active plugin on the "Plugins" page.

Roland Rust

Prints out your webservers php settings as well as other information about your WordPress installation. 
Important for posting at various WordPress support forums.

Phpinfo

Prints out your webservers php settings as well as other information about your WordPress installation.

Quick Configuration Links vs Phpinfo