WordPress custom post type taxonomy list filters

gistfile1.php

<?php

/**
 * Taxonomy list filters and columns
 *
 * @todo Test!
 * @todo Need replacement function for slt_terms_list()
 * @link http://wordpress.stackexchange.com/questions/578/adding-a-taxonomy-filter-to-admin-list-for-a-custom-post-type/3215#3215
 */
add_action( 'restrict_manage_posts', 'pilau_restrict_manage_posts' );
function pilau_restrict_manage_posts() {

    // only display these taxonomy filters on desired custom post_type listings
    global $typenow;
    if ($typenow == 'photos' || $typenow == 'videos') {

        // create an array of taxonomy slugs you want to filter by - if you want to retrieve all taxonomies, could use get_taxonomies() to build the list
        $filters = array('plants', 'animals', 'insects');

        foreach ($filters as $tax_slug) {
            // retrieve the taxonomy object
            $tax_obj = get_taxonomy($tax_slug);
            $tax_name = $tax_obj->labels->name;
            // retrieve array of term objects per taxonomy
            $terms = get_terms($tax_slug);

            // output html for taxonomy dropdown filter
            echo "<select name='$tax_slug' id='$tax_slug' class='postform'>";
            echo "<option value=''>Show All $tax_name</option>";
            foreach ($terms as $term) {
                // output each select option line, check against the last $_GET to show the current option selected
                echo '<option value='. $term->slug, $_GET[$tax_slug] == $term->slug ? ' selected="selected"' : '','>' . $term->name .' (' . $term->count .')</option>';
            }
            echo "</select>";
        }
    }
}

add_filter( "manage_edit-project_columns", "pilau_project_columns" );
add_action( "manage_posts_custom_column", "pilau_custom_post_columns" );
function pilau_project_columns( $columns ) {
	$columns[ "projecttype" ] = "Type(s)";
	$columns[ "worktype" ] = "Work";
	return $columns;
}
function pilau_custom_post_columns( $column ) {
	if ( $column == "projecttype" ) {
		echo slt_terms_list( "projecttype" );
	} else if ( $column == "worktype" ) {
		echo slt_terms_list( "worktype" );
	}
}