Josh Betz

Changes the Short URL and the Twitter Tools URL for each post on your site using a custom, shortened domain and a base-36 encode of the post ID.

JB Shortener

Changes the Short URL and the Twitter Tools URL for each post on your site using a custom, shortened domain and a base-36 encode of the post ID.

Prasanna SP

This plugin shows Tiny URL for each of your blog posts after post content. Tiny URLs are great for sharing your posts on micro-blogging sites like twitter, identi.ca etc., This plugin sends the URL of current post or page to <a href="http://tinyurl.com" rel="nofollow ugc">TinyURL.com</a> and gets a Tiny URL for the same. Then it shows that Tiny URL after post content. User can just click on the box to select URL, or click on Copy button to Copy the Tiny URL to clipboard. You can also show Tiny URL for pages by selecting Show Tiny URL on pages option in plugin settings page.
Note: Please read TinyURL’s <a href="http://tinyurl.com/#terms" rel="nofollow ugc">terms of use</a> before activating the plugin. You must abide by them after activating the plugin. TinyURL is a trademark of TinyURL, LLC
Demo: See demo of this plugin here – <a href="http://demo.prasannasp.net/tiny-url/" rel="nofollow ugc">Tiny URL WordPress plugin demo</a>
Support: Please post your support questions at <a href="http://forum.prasannasp.net/forum/plugin-support/tiny-url/" rel="nofollow ugc">Tiny URL plugin support forum</a>
Visit <a href="http://www.prasannasp.net/wordpress-plugins/" rel="nofollow ugc">this page</a> for more WordPress Plugins from the developer.
<h4>How to style the output?</h4>
The output of this plugin is wrapped in <code></code> tag. Use <code>.tiny-url</code> CSS class to style it 
Example,
<pre><code>.tiny-url {
color: #FF0000;
}
</code></pre>
<h4>How to change the style of Copy button?</h4>
Use CSS class <code>.tiny-url-button</code> to change it’s style. 
Example:
<pre><code>.tiny-url-button {
background: #123456;
color: #654321;
}
</code></pre>

Tiny URL

Show a Tiny URL for all of your blog posts and optionally for pages

JB Shortener vs Tiny URL