dataListening.js

jQuery.fn.dataWithoutTriggering = jQuery.fn.data;

jQuery.fn.data = function(key, value) {
  var r = this.dataWithoutTriggering(key, value);
  if (typeof(value) != "undefined") {
    this.trigger('data', [key, value]);
  }
  return r;
};

$(model).bind('data', function(key, value) {
 ... do custom stuff here if you want ...
});

function onData(boundKey, fn) {
  $(document).bind('data', function(key) {
    if (key == boundKey) fn();
  });
}