ce l'ho fatta, funziona.. grazie..
ho modificato il codice così:


codice:
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
 <script type="text/javascript" href=""></script> <script type="text/javascript"> 
jQuery.noConflict();

 jQuery(document).ready(function(){  jQuery(".galleria").mouseover(function() { 	  jQuery(this).animate({opacity: 1}, 1000);       }).mouseout(function(){ 	  jQuery(this).animate({opacity: 0.3}, 1000);   }); });  
</script> 
<style> .galleria { opacity:0.3} </style>

va bene?
grazie!!