Mega Code Archive
Matches all elements that have no children (including text nodes)
<![CDATA[
< html>
<head>
<script type="text/javascript" src="js/jquery-1.3.2.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("td:empty").text("Was empty").css('background', 'rgb(255,220,200)');
});
</script>
</head>
<body>
<table>
<tr><td>data</td><td></td></tr>
</table>
</body>
</html>
]]>