Always show Kitchen Sink in WordPress WYSIWYG Editor (so you don't have to explain this to clients every time ;-))

gistfile1.php

<?php
// Always show Kitchen Sink in WYSIWYG Editor
add_filter( 'tiny_mce_before_init', 'yourprefix_unhide_kitchensink' );
function yourprefix_unhide_kitchensink($args) {
	$args['wordpress_adv_hidden'] = false;
	return $args;
}