Clicar e Arrastar

<html>
<head>
<title>Exemplo</title>
<link type="text/css" href="css/ui-lightness/jquery-ui-1.8.2.custom.css" rel="stylesheet" />
<script type="text/javascript" src="js/jquery-1.4.2.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.8.2.custom.min.js"></script>
<style type="text/css">
#draggable { width: 150px; height: 150px; padding: 0.5em; }
</style>
<script type="text/javascript">
$(function() {
$("#draggable").draggable();
});
</script>
</head>
<body>
<div id="draggable" class="ui-widget-content">
<p>Drag me around</p>
</div>
</body>
</html>