One of the coolest features about Apache is that it allows you to branch off of the normal URL (GET) string in your queries and have things that don't make sense normally, but still will work effectively. Take for example, one of the more famous Apache Rewrite rules from the PHP.net website. If you type in http://www.php.net/str_replace, you magically get the manual page for the str_replace function. Well, it's not exactly magic, and SitePoint is here to help dispel the myths.

In mod_rewrite: A Beginner's Guide to URL Rewriting, they introduce you to the Apache mod_rewrite module and how to use it effectively. Not only can it make your site easier to navigate, but search engines can index "php.net/st_replace" much easier than they can "php.net?term=str_replace&page=1&foo=bar" and so on. They start you off small, with a simple rule that allows you to replace a simple product number on the query string, and quickly move into something more detailed - something like what I'm sure SitePoint is using themselves for their articles.

And, if you want to get really advanced with it all - they even cover an advanced set of rewrite rules to replace something that's a few categories deep into your site.