jQuery text implosion

See:http://stackoverflow.com/questions/6538546/jquery-animated-text/6538963#6538963

HTML

<div style="padding:200px;"><span onclick="fx(this)">click here</span></div>

JavaScript

function fx(o)
{
  var $o=$(o);
      $o.html($o.text().replace(/([\S])/g,'<span>$1</span>'));
      $o.css('position','relative');
      $('span',$o).stop().css({position:'relative',
                               opacity:0,
                               fontSize:84,
                               top:function(i){return Math.floor(Math.random()*500)*((i%2)?1:-1);},
                               left:function(i){return Math.floor(Math.random()*500)*((i%2)?1:-1);}
                               
                       }).animate({opacity:1,fontSize:12,top:0,left:0},1000);

}