Haris Zulfiqar

WordPress tooltip plugins lets you add tooltips to plain text and links on your post and pages.
It offers a tinyMCE shortcode GUI which will guide you through the entire process of a tooltip.
This plugin uses jQuery tipTip authored by Drew Wilson http://code.drewwilson.com/entry/tiptip-jquery-plugin.
You can also add tooltips manually by following the pattern below:
<pre><code>[tooltip content="This will show in a tooltip" url="This will make tooltip a link"]Hover over me for tooltip[/tooltip]
</code></pre>
Url is optional. If URL is added, it will render a link otherwise it will be a plain text.

WordPress Tooltip

WordPress tooltip lets you add tooltips to content on your posts and pages.

Thomas

Really simple plugin that allows you to easily add tooltips to your posts using the shortcode [wpetp].
It was made for some simple tooltips with text and/or images. For example if you want a way to add some information about a word in your post without forcing the user to leave the page to see them.
Feel free to ask for some features if you think I missed some.
Languages: English.

WP Easy Tooltips

Simple plugin that allows you to easily add tooltips to your posts using a shortcode.

WordPress Tooltip vs WP Easy Tooltips