title: Tutorials or screencasts on building a REST web service on Rails
body: <p>I am looking to build a <strong>REST webservice</strong> on Rails to serve as the <strong>server side component to my mobile app</strong>. Can someone point out some <em>tutorials</em> or <em>screencasts</em> on building REST webservices for someone who is learning Rails?</p>
  
  <p>The main features I am looking for are:</p>
  
  <ol>
  <li>Authorization(user id and password validation).</li>
  <li>Posting data from the client (mobile app) to the server database using REST API</li>
  </ol>
  
  <p>I am also okay if you could point me to some book where content on creating a rest api is available.</p>
  
  <p>It would also be great if someone could post a bit of code to get me started on this.</p>
  
  <p>I am relatively new to Rails and have almost finished the book "Ruby on Rails Tutorials" by Michael Hartl. This is my only experience with Rails, so far.</p>
  
  <p>Thanks.</p>