Shortcodes are a nice way of doing complex things within a post, without having to push PHP code through ExecPHP or one of those other plugins. Many plugins already make use of short codes allowing you to easily insert information into your posts.
Smashing Magazine has done a great job of explaining WordPress Shortcodes, how you can take advantage of them, and even write your own.
Introduced in WordPress 2.5, shortcodes are powerful but still yet quite unknown WordPress functions. Imagine you could just type “adsense” to display an AdSense ad or “post_count” to instantly find out the number of posts on your blog.
WordPress shortcodes can do this and more and will definitely make your blogging life easier. In this article, we’ll show you how to create and use shortcodes, as well as provide killer ready-to-use WordPress shortcodes that will enhance your blogging experience.
Of course you can go too overboard with these sorts of things, so I recommend limiting your shortcodes to less than five items, but it can be a great way to speed up what could be otherwise monotonous work when blogging.