foundation-topbar-menu.php and foundation-topbar-walker.php should be required in the WordPress functions.php file.
The code in foundation-topbar.php should be added below the body tag in header.php
Setup a menu in WordPress admin under Appearance > Menus
Use the 'label' class on a menu item to create a menu section title
Foundation Top Bar Doc: http://foundation.zurb.com/docs/components/top-bar.html
"Notice: Indirect modification of overloaded property WP_Post::$classes has no effect in ../functions.php on line 566"
"Notice: Trying to get property of non-object in .../wp-includes/nav-menu-template.php on line 88"
Any guesses? WordPress 3.5.2