<style type="text/css">
#middle {position: absolute; top: 50%;} /* for explorer only*/
#middle[id] {vertical-align: middle; width: 100%;}
#inner {position: relative; top: -50%} /* for explorer only */
</style>
<body style="background-color:#eeeeee">
<div id="middle">
<div id="inner" align="center" style="margin-top:...px"> /* the number will be half the height of your image, so for example if the height is 500px then you will put 250px for the margin-top */
<img src="..." height="..." width="..." />
</div>
</div>
</body>