Add a WordPress nav menu in content with a shortcode. Helpful for HTML sitemaps and the like

nav-menu-shortcode.php

<?php
/*
Plugin Name: Nav Menu Shortcode
Plugin URI: http://christopherdavis.me
Description: Add a shortcode to display a given nav menu
Version: 1.0
Author: Christopher Davis
Author URI: http://christopherdavis.me
License: GPL2

    Copyright 2012 Christopher Davis

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2, as 
    published by the Free Software Foundation.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/


add_action('init', 'cd_mei_add_shortcode');
/**
 * Adds the shortcode `list_menu`
 *
 * @since       1.0
 * @uses        add_shortcode
 * @return      null
 */
function cd_mei_add_shortcode()
{
    add_shortcode(
        'list_menu',
        'cd_mei_shortcode_cb'
    );
}


/**
 * Callback function for the `list_menu` shortcode.  Basically a thin wrapper
 * around `wp_nav_menu` that spits out the items.
 *
 * @since       1.0
 * @uses        wp_parse_args
 * @uses        wp_nav_menu
 * @param       array $args The associative array of shortcode args passed into
 *              the function
 * @return      string The menu
 */
function cd_mei_shortcode_cb($args)
{
    $args = wp_parse_args($args, array(
        'menu'        => 'sitemap',
        'class'       => 'sitemap-container',
        'container'   => 'div'
    ));

    return wp_nav_menu(array(
        'fallback_cb'     => false,
        'menu'            => $args['menu'],
        'container'       => $args['container'],
        'container_class' => $args['class'],
        'echo'            => false
    ));
}