define() or $variable for application settings?

Hello Everyone, I have a config.inc.php file which basically contains all the configuration info that the applications needs (directory/file locations, database credentials, etc). The information there is set using the define() function. However, I've seen some open-source projects which either use $variables or associative arrays to save the values. My application works pretty fine but I'd like to solicit opinions from everyone on what they are using in this case. Also, I have plans of putting up a sort of coding guidelines for the company so it might help to have other opinions on this one. Thanks and best regards, Matt -- Stand before it and there is no beginning. Follow it and there is no end. Stay with the ancient Tao, Move with the present.