https://github.com/pieterjongsma/ember-google-ajax-crawling/blob/master/lib/assets/javascripts/ember_hash_exclamation.js

ember_hash_exclamation.js

var get = Ember.get, set = Ember.set;

Ember.HashExclamationLocation = Ember.Object.extend({
  init: function() {
    set(this, 'location', get(this, 'location') || window.location);
  },
  
  getURL: function() {
    return get(this, 'location').hash.substr(2);
  },

  setURL: function(path) {
    exclam_path = '!'+path;
    get(this, 'location').hash = exclam_path;
    set(this, 'lastSetURL', exclam_path);
  },

  onUpdateURL: function(callback) {
    var self = this;
    var guid = Ember.guidFor(this);

    Ember.$(window).bind('hashchange.ember-location-'+guid, function() {
      var path = location.hash.substr(2);
      if (get(self, 'lastSetURL') === path) { return; }

      set(self, 'lastSetURL', null);

      callback(path);
    });
  },

  formatURL: function(url) {
    return '#!'+url;
  },

  willDestroy: function() {
    var guid = Ember.guidFor(this);

    Ember.$(window).unbind('hashchange.ember-location-'+guid);
  }
});

Ember.Location.registerImplementation('hash_exclamation', Ember.HashExclamationLocation);