Tocando Mongolab desde rails3

$ gem install rails

$ rails new touchMongoLab --skip-active-record
$ cd touchMongoLab

# Edit this Gemfile to bundle your application's dependencies.
require 'rubygems'
require 'mongo'
source 'http://gemcutter.org'

gem 'rails', '3.1.0.beta1'
gem "mongo_mapper"

$ bundle install

MongoMapper.connection = Mongo::Connection.new('namexyz.mongolab.com', port )
MongoMapper.database = "dbname"
MongoMapper.database.authenticate('user','passwd')

if defined?(PhusionPassenger)
   PhusionPassenger.on_event(:starting_worker_process) do |forked|
	 MongoMapper.connection.connect_to_master if forked
   end 
end

class User
  include MongoMapper::Document
  key :name
end

$ rails console
ruby-1.9.2-p180 :006 > user= User.new(:name => "hola mundo")
 => #<User _id: BSON::ObjectId('4dd097464cfad1e8ab000003'), name: "hola mundo"> 
ruby-1.9.2-p180 :006 > user.save()
 => true 

> db.users.find()
{ "_id" : ObjectId("4dd097604cfad1e8ab000004"), "name" : "hola mundo" }