Nikolay Kolev

The ShortURL plugin allows you to use your blog as your own URL shorterning service by implementing the <a href="http://wiki.snaplog.com/short_url" rel="nofollow ugc">Short URL Auto-Discovery</a> specification. Your short URLs will be in the form of <code>http://domain/-code</code>.
The auto-discovery feature allows third-party services that honor it to use your own short URLs instead of generating new ones using services such as <a href="http://tinyurl.com/" rel="nofollow ugc">TinyURL</a>, <a href="http://bit.ly/" rel="nofollow ugc">bit.ly</a>, and others. This gives your posts and pages canonical short URLs that give you all SEO benefits and don’t leak traffic out to external domains and will prevent linkrot. The homepage short URLs is set to just <code>http://domain/</code> as a unique feature.
The other great benefit of the ShortURL plugin is that the generated short URLs won’t break if you change the permalink structure of your blog or rename the slug of a particular post or page.
Due to the recent choice of both the <a href="http://microformats.org/" rel="nofollow ugc">Microformats</a> community and <a href="http://wordpress.com/" rel="nofollow ugc">WordPress.com</a> to use <code>rel="shortlink"</code> vs the alternative proposals, the ShortURL plugin is also using it now.
More on the topic:
<ul>
<li><a href="http://microformats.org/wiki/rel-shortlink" rel="nofollow ugc">Microformats Wiki: rel=”shortlink”</a></li>
<li><a href="http://en.blog.wordpress.com/2009/08/14/shorten/" rel="nofollow ugc">WP.me – shorten your links</a></li>
</ul>
<h3>To Do</h3>
<ul>
<li>Test against <a href="https://wordpress.org/" rel="ugc">WordPress</a> 2.9 and <a href="https://mu.wordpress.org/" rel="nofollow ugc">WordPress MU</a></li>
<li>Add a settings page</li>
<li>Add a widget</li>
<li>Integrated with <a href="http://www.google.com/analytics/" rel="nofollow ugc">Google Analytics</a></li>
<li>Integrate with the top <a href="http://twitter.com/" rel="nofollow ugc">Twitter</a> plugins to use ShortURL instead of third-party services</li>
</ul>

ShortURL

The ShortURL plugin provides short canonical permalinks to your posts and pages similarly to WordPress.com via its WP.me service.

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

ShortURL vs RevCanonical