mapdemo.js

var async = require('async');

var data = [
  {timeout: 43, text: 'taco bell'},
  {timeout: 26, text: 'twelve'},
  {timeout: 340, text: 'kfC'}
];

var counter = 0;
var iterator = function (item, callback) {
  setTimeout(function () {
    var result = (++counter) + ': ' + item.text;
    callback(null, result);
  }, item.timeout);
};

async.map(data, iterator, function (err, results) {
  console.log(err);
  console.log(results);
});