fosk

/* PASTE THESE LINES IN THE CSS SECTION OF YOUR THEME */
.shuffle {
    position: fixed;
    top: 3px;
    left: 3px;
    margin: 0;
    padding: 0;
    _position: static;
    _margin: 3px;
    _text-align: right;
    z-index: 1;
}
.shuffle a img {
    border: 0;
}


<!-- PASTE THESE LINES SOMEWHERE IN THE BODY HTML -->

<script type="text/javascript">
function shuffle() {
  var s1='<p class="shuffle"><a href="http://YOUR-TUMBLR-NAME.tumblr.com/';
  var s2='</a></p>';
  Total=0+64;
  if(Total>0) {
      var r=Math.ceil(Math.random() * Total);
      document.write(s1+'page/'+r+'">'+'<img src="http://data.tumblr.com/OY9NpboAI1s7qus3Dvw52nRC_500.png" width="70" height="20">'+s2);
  }
}
shuffle();
</script>