uhm.. well
uhm you could probably do something like
<style>
a:link { background-image:url('myimage.jpg'); }
a:hover { background-image:url('myimage2.jpg'); }
</style>
and for the links you will neeed a completely transparent png or gif
<a href="location.php"><img style="width:200px;height:100px;"></a>
of course change the width/height to whatever the background image is.. not sure if that would work.. but you could try.