Magic Words lets you effortlessly react to "magic" key sequences on your web page.

magic_words.js

/* Note! Requires jQuery right now :( */

var MagicWords = {
  spoken: [],
  data: undefined,
  init: function(d) {
    MagicWords.data = d;
    
    MagicWords.longest = 0;
    for(var i in MagicWords.data) {
      if (typeof MagicWords.data[i].words == 'string' || MagicWords.data[i].words instanceof String) {
        var x = [];
        for(var j in MagicWords.data[i].words)
          x[j] = MagicWords.data[i].words.charCodeAt(j);
        MagicWords.data[i].words = x;
      }
      MagicWords.longest = Math.max(MagicWords.longest, MagicWords.data[i].words.length);
    }
    var i = MagicWords.longest
    while(i-->0)
      MagicWords.spoken.push(-1);
    $(document).on("keypress", MagicWords.do_press);
    $(document).on("keydown", MagicWords.do_down);
  },
  do_press: function(e) {
    if(e.charCode>0)
      MagicWords.do_the_do(e.charCode);
  },
  do_down: function (e) {
    if(e.keyCode == 9 || // Tab
        (e.keyCode >=37 && e.keyCode <= 40)  // Arrow keys
      )
        MagicWords.do_the_do(e.keyCode);
  },
  do_the_do: function(n) {
    MagicWords.spoken.push(n);
      
    while(MagicWords.spoken.length>MagicWords.longest)
      MagicWords.spoken.shift();
    
    var wordWasSpoken = MagicWords.spoken.join(',');
    for(var i in MagicWords.data) {
      var wordToTest = MagicWords.data[i].words.join(',');
      var loc = wordWasSpoken.indexOf(wordToTest);
      var loc_want = wordWasSpoken.length-wordToTest.length;
      if(loc>-1 && loc == loc_want)
      {
        MagicWords.data[i].magic();
      }
    }
  }
}

/********* Examples *********/

MagicWords.init([{
    words: "the googs",
    magic: function() { window.location.href = 'http://google.com'; }
}]);

MagicWords.init([{
    words: [38, 38, 40, 40, 37, 39, 37, 39, 66, 65],
    magic: function() { alert('Everyone loves the Konami Code!') }
}]);