jQuery.fn.slideFadeToggle = function(speed, easing, callback) {
  return this.animate({opacity: 'toggle', height: 'toggle'}, speed, easing, callback);  
};

$(document).ready(function() {
  $('#fade').click(function() {
    $(this).next().slideToggle('slow', function() {
      var $this = $(this);
    });
  });
});