How to act on paramters being passed to the homepage? We have external sites direct users to our homepage. These external sites add information to the url which add additional information. This is an internal academic site so these parameters look like, for example, http://www.example.edu/?dept=classics
How can I get our homepage to detect and act on these parameters?
I think my approach would be to use $_SERVER['REQUEST_URI'] in a hook_preprocess_HOOK (see this) on template.php in a theme folder if all I needed to do is theming based on it.  For example:

function example_preprocess_page(&amp;$variables) {
  $current_path = $_SERVER['REQUEST_URI'];
  // and so on
}


And then you could explode() it, modify stuff in the page array or the node array, etc.