Recently, someone was asking me how to modify the items of a particular menu within a Drupal powered site. In particular, they wanted to modify all but the last menu item. This is where the Drupal API comes to the rescue with its theme_menu_link function. This function allows you to manipulate your menu items as you see fit. Want to add a unique class to a particular menu item? Need to add a string to only certain menu items? Want to replace the menu completely?