Global functions

[eluser]mabright[/eluser]
I'm probably over thinking and missing the obvious but I have a common template view that I call from every controller and I include other view data in the template view based on page. The template view has a header area that I want displayed on every page. In the header area I have a section that displays data based on IP address and the data is dynamically determine so I cannot just hard code a global variable in the config.php file.

I there a way to define some global include/function and have it called from the config.php file to build my dynamic content and put it in a global variable so that it can be used in my template view?