Wordpress > Dynamic sidebar generator and selector UI.

sidebar-selector.php

 <?php
     ## Replace Array of Sidebars with Your Choice of Names, Each will be generated
     $dynamic_widget_areas = array(
        /* rename or create new dynamic sidebars */
        "Sidebar 01",
        "Sidebar 02",
        "Sidebar 03",
        "Sidebar 04",
        "Sidebar 05",
        "Sidebar 06",
        "Sidebar 07",
        "Search Template",
    );

    if ( function_exists('register_sidebar') ) {
        foreach ($dynamic_widget_areas as $widget_area_name) {
            register_sidebar(array(
               'name'=> $widget_area_name,
               'before_widget' => '<div id="%1$s" class="widget %2$s left half">',
               'after_widget' => '</div>',
               'before_title' => '<h3 class="widgettitle">',
               'after_title' => '</h3>',
            ));
        }
    }
    add_action("admin_init", "sidebar_init");
    add_action('save_post', 'save_sidebar_link');

    function sidebar_init(){
            add_meta_box("sidebar_meta", "Sidebar Selection", "sidebar_link", "page", "side", "default");
    }

    function sidebar_link(){
            global $post, $dynamic_widget_areas;
            $custom  = get_post_custom($post->ID);
            $link    = $custom["_sidebar"][0];
    ?>

    <div class="link_header">
        <?
        echo '<select name="link" class="sidebar-selection">';
        echo '<option>Select Sidebar</option>';
        echo '<option>-----------------------</option>';
        foreach ( $dynamic_widget_areas as $list ){
            if($link == $list){
              echo '<option value="'.$list.'" selected="true">'.$list.'</option>';
                }else{
              echo '<option value="'.$list.'">'.$list.'</option>';
                }
        }
        echo '</select><br />';
        ?>
    </div>
    <p>Select sidebar to use on this page.</p>
    <?php }

    function save_sidebar_link(){
    global $post;
    if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {return $post->ID;}
            update_post_meta($post->ID, "_sidebar", $_POST["link"]);
    }
    add_action('admin_head', 'sidebar_css');

    function sidebar_css() {
        echo'
        <style type="text/css">
                .sidebar-selection{width:100%;}
        </style>
        ';
} ?>

remove this code

add_action('admin_head', 'sidebar_css'); function sidebar_css() { echo' <style type="text/css"> .sidebar-selection{width:100%;} </style> '; }

and replace "sidebar-selection" class with "widefat" in this line

echo '<select name="link" class="sidebar-selection">';