craigsimps

This is a super-simple plugin which will turn WordPress’ default <code>/?s=query%20terms</code> into <code>/search/query+terms/</code> if you have pretty permalinks enabled.
This is something which I have been placing into a theme include or in a core functionality plugin until recently, but it makes sense to separate this functionality out into an individual plugin so it can be switched on and off independently.
The plugin has no administrative interface or control panel. Activation turns it on, deactivation turns it off. Once activated, performing a search using the standard WP search widget should give you a much nicer search URL.

Simple Search Rewrite

Redirects search results from /?s=query to /search/query/, and converts %20 to +.

gokulakrishnan

You can create unlimited redirections and rewrites. A redirect and rewrite can be used in many situations, for example:
<ul>
<li>to hide an url you don’t want to show;</li>
<li>to short a long url;</li>
<li>to monitor the traffic of an url;</li>
<li>to redirect the users in another page during a maintenance;</li>
<li>to redirect user from a dormiant domain;</li>
<li>to rewrite the content with customized urls </li>
<li>to customize whatever name you want</li>
</ul>
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Url Redirect Rewrite

Manage Unlimited Redirections and Rewrites

Simple Search Rewrite vs Url Redirect Rewrite