lautr

This Plugin implements an easy configurable Widget which can display your top Google search querys (Keywords) and link it to your internal search like a tag cloud by accessing an Google Analytics account. 
You can use its default font sizes or override them by the classes that are applied. It is recommended to have APC installed to cache the Google API requests but its not necessary. 
It is written and currently maintained by <a href="http://www.lautr.com" rel="nofollow ugc">Johannes Lauter</a> and uses the Google Analytics API PHP Class from <a href="http://www.electrictoolbox.com" rel="nofollow ugc">Chris Hope</a>.

WP Google Search Query Widget WordPress Plugin

Implements a Widget with your Top Google Search Querys

Fabio M. Giacomini

This plugin adds a new field in every post, where you can write a text that will be inserted in the related meta tag, located in the head section.
The main options page of the plugin, provides you with a default text area, where you can insert a default description that will appear in case the field in post page is empty.

Single Post Meta Description

The easiest way to add in every post page a different meta description tag, located in html head.

WP Google Search Query Widget WordPress Plugin vs Single Post Meta Description