Konami Code jQuery Plugin

jquery.konamiCode.js

/*
 * Konami Code jQuery Plugin
 *
 * Usage:
 *
 *  1 - Set permanent callback: everytime the user makes the 
 *                              konami code the callback will 
 *                              be called.
 *
 *  $(document).konamiCode(callback, true)
 *
 *
 *  2 - Non permanent callback: callback will be called only
 *                              in the next konami code
 *
 *  $(document).konamiCode(callback, false)
 *  $(document).konamiCode(callback)
 *
 *
 * 3 - Call konami code without user interation:
 *
 * $(document).konamiCode()
 *
 *
 *
 * Copyright 2013+ Gabriel "Gab!" Teles
 * Date: 2013/07/26
 */

(function($){
    $.konamiCode = {
        sequence:  [38,38,40,40,37,39,37,39,66,65],
        keys:      [],
        callbacks: [],

        execute: function(){
            $.grep($.konamiCode.callbacks, function(element, index){
                (element[0])(); // Callback
                return element[1];
            });
        }
    }

    $(document).keyup(function(e){
        code = e.keyCode;
        if ($.konamiCode.sequence[$.konamiCode.keys.length] == code){
            $.konamiCode.keys.push(code)
            if ($.konamiCode.keys.length == $.konamiCode.sequence.length){
                $.konamiCode.execute()
                $.konamiCode.keys = []
            }
        } else {
            $.konamiCode.keys = []
        }
    });

    $.fn.konamiCode = function(callback, permanent){
        if (typeof(callback) !== 'undefined')
            $.konamiCode.callbacks.push([callback, !!permanent]);
        else
            $.konamiCode.execute();

        return this;
    }
})(jQuery);