Ecco qua funziona con tutti i browser!
codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Documento senza titolo</title>
<style type="text/css">
<!--
#contenitore {
	clear: both;
	width: 2500px
}
img {
	float: left;
}
#clear {
	clear: both;
}
-->
</style>
</head>

<body>
      <div id="contenitore">
            [img]01.jpg[/img]
            [img]hat.jpg[/img]
            [img]somewhere.jpg[/img]
            <div id="clear"></div>
      </div>
</body>
</html>