basta un po' di classe, per esempio
codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
<title>titolo</title>
<style type="text/css">
* {
margin: 0px;
padding: 0px;
list-style-type: none;
}
.container li {
width: 200px;
float: left;
background-color: #00FF00;
text-align: center;
}
.container li.ww {
width: auto;
float: none;
}
</style>
</head>
<body>
<div class="container">
<ul>[*]xfgh 1[*]xfgh 2[*]xfgh 3[*]xfgh 4
<li class="ww">xfgh 5[/list]
</div>
</body>
</html>