konami.js

/**
 * Trigger something totally inappropriate when user enters the
 * right sequence of the Konami code.
 *
 * callback is the function you want to execute when the complete sequence
 * has been entered.
 */

var konamiCode = function(callback) {

    // The famous Konami sequence in keycodes
    // up up down down left right left right b a
    var sequence = [38, 38, 40, 40, 37, 39, 37, 39, 66, 65];
    var ko = sequence;

    // Get the rest of this function's arguments (if any).
    // These will be used as the callback's arguments.
    var args = [];
    for (var i = 1; i < arguments.length; i++) {
        args.push(arguments[i]);
    }

    document.addEventListener('keydown', function(e) {
        if (e.keyCode == ko[0]) {
            ko.splice(0,1);
            if (ko.length === 0) {
                callback.apply(null, args);
            }
        } else {
            ko = sequence;
        }
    });
};