(function($) {
  var special = $.event.special,
      uid1 = 'D' + (+new Date()),
      uid2 = 'D' + (+new Date() + 1);

  special.scrollstart = {
    setup: function() {
      var timer,
          handler = function(evt) {
              var _self = this,
                  _args = arguments;

              if (timer) {
                clearTimeout(timer);
              } else {
                evt.type = 'scrollstart';
                $.event.handle.apply(_self, _args);
              }

              timer = setTimeout(function() {
                timer = null;
              }, special.scrollstop.latency);
          };

        $(this).bind('scroll', handler).data(uid1, handler);
      },
      teardown: function() {
        $(this).unbind('scroll', $(this).data(uid1));
      }
    };

    special.scrollstop = {
      latency: 250,
      setup: function() {
        var timer,
            handler = function(evt) {
              var _self = this,
                  _args = arguments;

              if (timer) {
                clearTimeout(timer);
              }

              timer = setTimeout(function() {
                timer = null;
                evt.type = 'scrollstop';
                $.event.handle.apply(_self, _args);
              }, special.scrollstop.latency);
            };

        $(this).bind('scroll', handler).data(uid2, handler);
      },
      teardown: function() {
        $(this).unbind('scroll', $(this).data(uid2));
      }
    };

})(jQuery);