Character Count

http://wpsnipp.com/index.php/excerpt/add-a-character-counter-to-excerpt-metabox/
TR

/* Add character count to Excerpt box */
function tr_excerpt_char_count()
{ ?>
    <script type="text/javascript">
    jQuery(document).ready(function(){
		jQuery('#postexcerpt p').append(' <em id="excerpt-char-cnt"></em>');
	    jQuery('#excerpt').focus(function(){
	        jQuery('#excerpt-char-cnt').html('Char count: <span>' + jQuery('#excerpt').val().length + '</span>');
	    });
	    jQuery('#excerpt').keyup(function(){
	        jQuery('#excerpt-char-cnt span').html(jQuery('#excerpt').val().length);
	    });
    });
    </script>
<?php }
add_action('admin_footer-post.php', 'tr_excerpt_char_count');
add_action('admin_footer-post-new.php', 'tr_excerpt_char_count');

http://wpsnipp.com/index.php/excerpt/add-a-character-counter-to-excerpt-metabox/

function excerpt_count_js(){
      echo '<script>jQuery(document).ready(function(){
jQuery("#postexcerpt .handlediv").after("<div style=\"position:absolute;top:0px;right:5px;color:#666;\"><small>Excerpt length: </small><input type=\"text\" value=\"0\" maxlength=\"3\" size=\"3\" id=\"excerpt_counter\" readonly=\"\" style=\"background:#fff;\"> <small>character(s).</small></div>");
     jQuery("#excerpt_counter").val(jQuery("#excerpt").val().length);
     jQuery("#excerpt").keyup( function() {
     jQuery("#excerpt_counter").val(jQuery("#excerpt").val().length);
   });
});</script>';
}
add_action( 'admin_head-post.php', 'excerpt_count_js');
add_action( 'admin_head-post-new.php', 'excerpt_count_js');