il title è importante per varie ragioni..
comunque ecco a te lo script che vuoi:
Codice PHP:
<html>
<head>
<script type="text/javascript">
onload=function(){
    var links = document.getElementsByTagName("a");
    for(var i=0,max=links.length;i<max;i++){
        var imgs = links[i].getElementsByTagName("img");
        var texts = links[i].getElementsByTagName("span");
        if(imgs && imgs.length==1 && texts && texts.length==1){
            texts[0].style.display="none";
            links[i].onmouseover=function(){
                texts[0].style.display="";
            }
            links[i].onmouseout=function(){
                texts[0].style.display="none";
            }
        }
    }
}
</script>
</head>
<body>
[url="auto_e_moto.htm"][img]immagine_auto_moto.gif[/img]<span class="title">auto e moto</span>[/url]
</body>
</html>