First Plugin: Arbitrary Shortcodes

This plugin allows you to write your page content like this: “Contact our company, [company_name], by email at: [email].”

Text with these shortcodes can be defined on any number of pages throughout your site.

The values of all of the shortcodes are controlled in a single location: the Custom Fields of your blog’s home page. For the above example, there would be Custom Fields on the home page called “company_name” and “email” with the values, respectively, of “Example Company Name” and “info@example.com”.

This plugin requires that you have WordPress set to show a static Page on the home page under Settings->Reading and “Front page”.

So then, for all the custom fields entered on the home page, this plugin looks for shortcodes (in all pages) and replaces each of their values, upon output, with the relevant custom field value.

This is useful for if you want to fill many pages with text that includes an arbitrary number of shortcodes or template text and have all the values can be replaced in one place.

Blog post: http://philfreo.com/blog/arbitrary-shortcodes/
Plugin page: http://wordpress.org/extend/plugins/arbitrary-shortcodes/