Best way to set global params for entire site??

I'm building a site with PHP and most scripts need access to certain site-wide global parameters, such as paths and default settings, etc. What's the best way to load this information so that it's globally available to all scripts? I have a func.php file that is included in all scripts - do I just load them every time for each script in there? Or is there a more efficient way of doing this with environment variables or some other way? Thanks!!