ajax-promise

var ajaxPromise = function(params) {
  var deferred = Q.defer(); // Create the promise

  $.ajax(params) // Create the call normally
  .error(function(err) {
    deferred.reject(err); // Causes ths promise to fail
  })
  .success(function(result) {
    deferred.result(result); // You probably want to standardize your results here
  });

  return deferred.promise;
};

// You can then create shortcut methods for post, get, etc...
ajaxPromise.post = function(params) {
  params.type = "POST";
  return ajaxPromise(params);
};
// etc...