load variables in template.php and make them available to some_file.tpl.php

Hi,

I've been researching how to use phptemplate callback to pass variables into template files but I cant get it working for my situation, which is as follows:

1. I want to load some variables in template.php (theme settings mostly, but thats irrelevant)
2. I want to pass them into some_file.tpl.php, this is not an existing function name or template file, its a brand new file
3. I then include this file in other files

Even better would be if I could pass the variables directly into this other file which is a regular php file, not a .tpl.php file - but I think this is not possible?

Any help would be greatly appreciated.

JR