BuddyPress.org

Basically, you just delete or not add the function and the closing tag that makes the sidebar dynamic or widgetized.

For example, open up WPMU’s default theme’s sidebar.php. You will see near the top of the file …

<div id="sidebar" role="complementary">

<ul>

<?php 	/* Widgetized sidebar, if you have the plugin installed. */

if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar() ) : ?>

<li>

<?php get_search_form(); ?>

</li>

etc

etc

etc

and the file ends ends with

<?php endif; ?>

</ul>

</div>

So you delete the

<?php 	/* Widgetized sidebar, if you have the plugin installed. */

if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar() ) : ?>

near the top of the sidebar.php file and delete

<?php endif; ?> near the bottom of the sidebar.php file

The codes before, in between and after these are hardcoded now. Your members cannot change anything in the sidebar.