oishikazuo

Self Shortener is a WordPress plugin to be able to handle URL shortening 
feature, by your WordPress site itself.
Self Shortener can:
<ul>
<li>create short URL using your site URL.</li>
<li>generate random short URL key, by specifying key length.</li>
<li>specify fix URL key instead of random generating.</li>
<li>handle I18N message. Currenly supports English and Japanese.</li>
</ul>
See http://giraffy.jp/products_en/wordpress/selfshortener/ . 
(In Japanese, http://giraffy.jp/products/wordpress/selfshortener/ )

Self Shortener

URL Shortener handled by your WordPress site itself.

Peter

Adds shortcodes [blogurl], [posturl], [templateurl], and [childtemplateurl] for WordPress 2.6 and up. Use [blogurl] to generate your site URL. It offers the parameters “slash” and “noslash” (to add a trailing slash; [templateurl] and [childtemplateurl] also support this), as well as “uploads” to produce the URL of the uploads folder and “wordpress” to produce the URL of your WP files. Use [posturl id=3] (replace “3” with a post ID) to generate the permalink for any post.
<h4>Features</h4>
<ul>
<li>
[blogurl] will generate <code>http://www.yoursite.com/</code>
</li>
<li>
[blogurl wordpress] will generate the URL to the root of your WordPress files, if they are in a different location than your site root
</li>
<li>
[blogurl noslash] will generate <code>http://www.yoursite.com</code>
</li>
<li>
[blogurl uploads] will generate <code>http://www.yoursite.com/wp-content/uploads/</code>
</li>
<li>
[blogurl uploads noslash] will generate <code>http://www.yoursite.com/wp-content/uploads</code>
</li>
<li>
[posturl id=375] will generate the correct permalink for the post with an ID of 375; for example, <a href=”[posturl id=375]”>post about this plugin</a> would generate <a href="http://www.theblog.ca/blog-url-shortcodes" title="From Peter's Useful Crap" rel="nofollow ugc">post about this plugin</a>
</li>
<li>
[templateurl] will generate the URL to your parent theme’s root
</li>
<li>
[childtemplateurl] will generate the URL to your child theme’s root
</li>
</ul>
<h4>Requirements</h4>
<ul>
<li>WordPress 2.6 or higher</li>
</ul>

Peter’s Blog URL Shortcodes

Use shortcodes for blog URLs, post URLs, and template URLs so that your posts always have the correct internal links.

Self Shortener vs Peter’s Blog URL Shortcodes