|As the major part in my PHP Application Architecture, this trick allows you to include a global file at the top of your scripts. It has the benefit of not keeping the file location or name inside of each individual PHP script.
I was able to accomplish this by using Apache's SETENV directive. It registers a variable visible to all scripting languages through either an entry in an .htaccess or httpd.conf file. Then in each of my PHP scripts I include that variable's contents.
A very handy trick, if you ask me.