jesseheap

This wordpress plugin ensures tags associated with a post are searched when users perform search using the out-of-box wordpress search feature. This plugin works with the new WordPress 2.3 native tagging features.
This plugin is beneficial for those that associate tags with posts that don?t appear in the post content.
<h3>Demo</h3>
See an example of this plugin at <a href="http://blog.pinkcakebox.com/" title="Wedding Gallery" rel="nofollow ugc">Wedding Cake Blog</a>

WP Search Tags

This wordpress plugin ensures tags associated with a post are searched when users perform search using the out-of-box wordpress search feature.

scibuff

Adds twitter search tags to the <a href="https://wordpress.org/extend/plugins/twitter-tools/" rel="ugc">Twitter Tools</a> 
automatic “New Blog Post” status using Twitter Tool’s <code>tweet_blog_post_url</code> hook. The plugin will 
add post tags as twitter search tags to the “New Blog Post” twitter status message (and also shorten 
the new post’s url using http://is.gd API).
Requirements
<ul>
<li><a href="https://wordpress.org/extend/plugins/twitter-tools/" rel="ugc">Twitter Tools</a> be installed and activated</li>
<li>PHP 5.2.0 or newer</li>
<li>WordPress 2.7 or newer</li>
</ul>

Twitter Tools Search Tags

Adds twitter search tags to the Twitter Tools automatic "New Blog Post" status using Twitter Tools.

WP Search Tags vs Twitter Tools Search Tags