How to act on paramters being passed to the homepage?
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.