Use jQuery.animate to animate over multiple elements

js.js

;(function($) {

    $.fn.popIn = function(dur) {
        var $all = this;
        
        $('<b>').animate({
            foobar: $all.length
        }, {
            easing: 'easeInOutBounce',
            duration: dur,
            step: function(now, fx) {
                $all.hide().slice(0, now | 0).show();
            }
        });
    };

})(jQuery);