Marcus Downing

When writing or modifying a theme, the function wp_nav_menu() displays the contents of menus configured in your settings. If you have a lot of little menus the list can get hard to manage, so this plugin lets you group several menus under a single menu.
To use it, simply add a <code>submenu</code> parameter to the arguments of wp_nav_menu, like so:
<pre><code>wp_nav_menu(array(
 'menu' => 'header',
 'submenu' => 'About Us'
));
</code></pre>

Subtitle Filter

Adds tha ability to show only a submenu with wp_nav_menu().

Pavel Revenkov

This plugin allows to extend the URL of standard menu items such as Post, Page Category, etc. When using Custom Link Type for these purposes then you have to correct the URL value, if the permalink of Post, Pages etc changed. If the site has got hundreds of Posts, Pages etc. it can become a complex task. This plugin helps you to improve flexibility and productivity when managing the menus.
For example to the end of URL you can add:
<ul>
<li>Fragment identifier (hashtag), i.e. ‘#contact’</li>
<li>Additional GET options, i.e. ‘?key1=val1&key2=val2’</li>
<li>Additional Human Readable part i.e. ‘filter/cars/ford/’</li>
<li>Or all the above together</li>
</ul>

Menu Item Extended URL

Allows to add additional parameters and/or fragment identifier (hashtag) to the menu item URL.

Subtitle Filter vs Menu Item Extended URL