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.

Chris Bratlien

Allows you to publish content during dev phase without having to go back and 
fix your content’s static URLs when you switch to the production URL. Registers [url] shortcode 
with your site’s base URL setting. Replaces occurances of http://mysite.com/the/link 
with [url]/the/link inside the content editor when you hit Publish or Update.
http://chrisbratlien.com/2010/05/16/relative-site-url-on-content-save/

Relative Site URL on Content Save

Allows you to publish content during dev phase without having to go back and fix your content's static URLs when you switch to the production URL …

Peter’s Blog URL Shortcodes vs Relative Site URL on Content Save