/* ----////// Эффект прозрачности by http://Sinners.PP.Ua /////------- */   

#banners a img {   
opacity:0.3; -moz-opacity:0.3; filter:alpha(opacity=40);   
}   

#banners a:hover img {   
opacity:1.0; -moz-opacity:1.0; filter:alpha(opacity=100);   
}

<div id="banners">Адрес картинки</div>

<div id="banners"><img alt="" src="http://116hp.clan.su/img/126.gif"></div>