[poorking]

Могу предложить такой вариант

<script type = "text/javascript">
window.onload = function(){		
		
function hasSubs(li){
	var subs = [];
	for(var i = 0, il = li.childNodes.length; i < il; i ++){
		if(li.childNodes[i].nodeName == "UL"){
			subs[subs.length] = li.childNodes[i];
		}
	}
	return subs;
}
		
function isLI(node){
	return node.nodeName == "LI";
}
		
function count(ul){
	var childs = ul.childNodes;
	for(var i = 0, il = childs.length; i < il; i ++){
		if(isLI(childs[i])){
			var subs = hasSubs(childs[i]);
			if(subs.length){
				for(var j = 0, jl = subs.length; j < jl; j ++){
					count(subs[j]);
				}
			}else{
				alert("item" + childs[i].innerHTML);
			}		
		}
	}			
}

var outer = document.getElementById("menu");	
count(outer);
}
</script>

<ul id = "menu">
	<li>1</li>
	<li>2</li>
	<li>3</li>
	<li>
		<ul>
			<li>4.1</li>
			<li>4.2</li>
			<li>4.3</li>
			<li>
				<ul>
					<li>4.4.1</li>
					<li>4.4.2</li>
					<li>4.4.3</li>
					<li>4.4.4</li>
				</ul>
			
			</li>
		</ul>
	</li>
	<li>5</li>
</ul>