akrabat

The Shorter Links WordPress plugin overrides the default WordPress 
“shortlink” URL with one that has a custom text in it. You can also set a 
different base URL.
A custom field called “Shorter link” is created once a post is saved, 
so that you can change the shortlink to a more memorable set of 
characters.
The choice of base URL to use for the short link can be configured within 
Settings->Shorter Links.
Related Links:
<ul>
<li><a href="http://akrabat.com/shorter-links" rel="nofollow ugc">Plugin home page</a></li>
</ul>
<h3>Licence</h3>
This plugin is licensed under the <a href="http://akrabat.com/license/new-bsd" rel="nofollow ugc">New BSD license</a>.
<h3>History</h3>
2.1.0 – 8 August 2015 
Rework to look for the shorter link after WordPress has done its processing. This 
means that a shorterlink that represents a date won’t affect an archive list.
2.0.6 – 8 August 2015 
Ensure that the short_link is correct when using a post id.
2.0.5 – 8 August 2015 
Updated Tested up to 4.3
2.0.3 – 9 July 2012 
Bug fix so that archives work.
2.0.2 – 23 June 2012 
Fall back to REQUEST_URI if there’s nothing interesting in $query_vars.
2.0.1 – 20 June 2012 
Updated to handle 4 digit short links that look like a year to WordPress.
2.0.0 – 21 November 2010 
Updated to be WordPress 3.0 or above, so we only need to hook into the WordPress 
shortlink system
1.8.2 – 21 November 2010 
Fix permissions issue on settings page. This is the last version that works 
on WordPress 2.9.x or earlier.
1.8.1 – 7 September 2010 
Bug fix to remove a warning.
1.8 – 1 September 2010 
use shortlink rather than shorturl for WordPress less than 3. 
For WordPress 3 or higher, hook into the new shortlink system. 
Fix the admin page so that it displays in WordPress 3.
1.7 – 11 Feburary 2010 
Handle failures better.
1.6 – 10 January 2010 
Update version number in correct places so that the WP plugins system notices the update.
1.5 – 29 December 2009 
Support permalinks that start with /%category%/
1.4 – 14 April 2009 
Support rel=”shorturl” as per <a href="http://sites.google.com/a/snaplog.com/wiki/short_url" rel="nofollow ugc">Robert Spychala’s Short URL Auto-Discovery proposal</a>.
1.3 – 14 April 2009 
Add support for setting the base URL. Patch by <a href="davemastergeneral@gmail.com" rel="nofollow ugc">Dave Marshall</a>.
1.2 – 13 April 2009 
Only send the <code>Link</code> HTTP header as recommended by <a href="http://shiflett.org/blog/2009/apr/a-rev-canonical-http-header" rel="nofollow ugc">Shiflett</a>.
1.1 – 13 April 2009 
Fixed output of HTTP headers. Patch by <a href="http://bethesignal.org/" rel="nofollow ugc">Jeff Waugh</a>.
1.0 – 11 April 2009 
Initial release.

Shorter Links

Override the default WordPress "shortlink" URL with one that has a custom text in it. You can also set a different base URL.

whomwah

RevCanonical generates a short url for your pages, as well as adding <a href="http://laughingmeme.org/2009/04/03/url-shortening-hinting/" rel="nofollow ugc">link shortening discovery</a>. You can use this url on character restricted sites like <a href="http://twitter.com" rel="nofollow ugc">Twitter</a>, in IM, or anytime you need a short link to your webpages. The discovery part means that other sites and <a href="http://revcanonical.appspot.com/" rel="nofollow ugc">services</a> can also use the short url should they need it. Oh and this short url is yours, from your website. It does not use any external service.
Here’s what gets added to your pages. The link in the href is the short version you can use:
<pre><code><link rev="canonical" type="text/html" href="http://my-domain.me/p12p" /> 
</code></pre>
This tag can though be customised to suit your own preferences (at your own risk), for instance this:
<pre><code><link rel="shortlink" href="http://my-mini.me/p12p" /> 
</code></pre>
That’s it! You can now, not only use this url to pass around, and in sites like <a href="http://twitter.com" rel="nofollow ugc">Twitter</a> without having to go via a url shortening service, but <a href="http://revcanonical.appspot.com/" rel="nofollow ugc">services</a> or people that understand the rev=canonical link tag, will be able to use this shortened version over the longer canonical version. It also means that it’s persistence is down to you, and not to a 3rd party.
Oh and there’s <a href="http://simonwillison.net/2009/Apr/11/revcanonical/" rel="nofollow ugc">a great bookmarklet</a> that makes hunting for existing short urls on a page really simple. You can read more about this plugin at my website http://littl.me/p136
NOTE: I use the Day and name style permalinks in WordPress. I can’t be sure the plugin will work if you use other formats.
What’s changed? View <a href="http://github.com/whomwah/revcanonical/raw/master/CHANGELOG" rel="nofollow ugc">the CHANGELOG</a>
<h3>Advanced</h3>
The default settings should suit most people, but if there are a couple of things you can change should you wish. There are also a few tags you can use within your own pages.
If your domain name is a bit long and you own a smaller domain you would like to use as your shortened domain, you can add this in the settings page. You would then just need to make sure that the new domain pointed to the original via a ProxyPass setting.
There are many ongoing conversations on the web about how to describe shortened links in HTML. There appears to be no absolute right way, so by default if will be rev=canonical. Should you want to use another way, you can also change this via the settings page.
And finally… there are a couple of tags you can use in your own templates, that will return the short link for that page. You need to pass them the post ID.
<pre><code><?php get_revcanonical_link($post->ID) ?> ===> Echo the shorturl to the screen

<?php $url = revcanonical_link($post->ID) ?> ===> Assign the shorturl to a variable
</code></pre>

RevCanonical

A Wordpress plugin that creates and adds support for shortened urls plus the shortlink auto-discovery tag

Shorter Links vs RevCanonical