title: Can I use rails' devise to integrate linkedin connect to my site?
body: <p>I have a Rails 3 application using Devise for authentication. <br>In addition to the manual authentication using email, I also have a facebook connect that allows a single sign-in using facebook. <br>The next step is linkedin connect. Is there a simple way to integrate linkedin API call to devise?
  <br>(The naive approach of defining 
  <br><code>
  config.oauth :linkedin, 'MY_APP_ID','MY_APP_SECRET',<br>
        :site              => 'https://api.linkedin.com/',<br>
        :authorize_path    => '/uas/oauth/authorize',<br>
        :access_token_path => '/uas/oauth/accessToken'<br></code>
  in the config/initializers/devise.rb resulted in "An Authorization Token was not supplied" error message from linkedin).</p>
  
  <p>Thanks!</p>
  
  <p>Update:
  Thanks for the (incredibly) fast replies. I was hoping not to have to change my application to add the linkedin authentication, by using omniauth or a similiar solution. However, I now see that the linkedin response doesn't return the email - which is the used as the primary key for my users, and hence I cannot use the authentication the way I use facebook (In Ryan's solution he allows to define the email separately if not returned from twitter, but it's not good enough for my purposes).</p>
  
  <p>Another Update:
  Devise now has omniauth support, and it is working nicely.
  Checkout <a href="https://github.com/plataformatec/devise/wiki/OmniAuth%3a-Overview" rel="nofollow">this link</a>.</p>