snippet.txt

var EasternEggTrigger = function(sequence, callback) {

  var seqString = sequence.join(' '),
  seqLength = sequence.length,
  got = [],
  d = document,
  handler = function(e) {
    e = e || window.event;
    got.push(e.keyCode);
    if (got.join(' ').indexOf(seqString) !== -1) {
      got = [];
      callback();
    }
    else if (got.length > seqLength) {
      got.shift();
    } 
  };

  if (d.addEventListener)
    d.addEventListener('keydown', handler, false);
  else if (d.attachEvent)
    d.attachEvent('onkeydown', handler);

};

EasternEggTrigger([ 38, 38, 40, 40, 37, 39, 37, 39, 66, 65 ], function() {
  document.body.appendChild(document.createTextNode('yay!'));
});