var isAnimating = false;

$('.toggle').click(function() {

    //Only run it if it's not animating
    if(!isAnimating) {

        isAnimating = true;

        menu.toggleClass('open');

        item = $('.item');

        $.each($(item), function(i, el) {

            $(el).css({'opacity': 0});

            setTimeout(function() {
                $(el).toggleClass('open').animate({
                    'opacity': 1.0
                }, 450);
            },50 + ( i * 200 ));

        });

        //It just triggers it as many times as there are elements..
        isAnimating = false;
    }
});