Customizing menu link output In Drupal 7, how I can intercept menu rendering in template.php and add pipes after menu links?

I tried using template_preprocess_menu_tree but I don't think that is what I am looking for. I want to change the HTML structure of a couple of menus.
theme_menu_link() did the trick. It contains an array under element of #original_link which has the menu name in it. Using that, I can add pipe delimited links to certain menus.

http://api.drupal.org/api/drupal/includes--menu.inc/function/theme_menu_link/7