Print current wordpress template hierarchy.

template_hierarchy_debug.php

<?php 
/** 
 * Show template hierarchy and theme at the end of the request/page.
 * @return void
 */
function wpse31909_template_info()
{
        // Don't display for non-admin users
        if ( ! current_user_can( 'manage_options' ) )
            return;

        // You have to build yourself the hierarchy here or somewhere in front of the fn
        global $wp_template_hierarchy;

        $content  = '<pre>';
            // Show template hierarchy
            $content .= "TEMPLATE HIERARCHY\n==================\n";
            $content .= var_export( $wp_template_hierarchy, true );

            // Show current theme in use:
            $content .= "\n\nCURRENT THEME\n=============\n";
            $content .= var_export( get_option( 'template' ), true );
            // or: 
            # $content .= var_export( get_template(), true );
        $content .= '</pre>';

        return print $content;
}
add_action( 'shutdown', 'wpse31909_template_info' );