title: OAuth with DotNetOpenAuth?
body: <p>Ok here is my question.
  I understand the process of the OAuth protocol, however I have some confusion around it.
  I'm trying to take advantage of DotNetOpenAuth.Here is where I don't get things.
  Suppose a user (a new user), attempts to login to my website using Twitter.
  The process goes like this (feel free to correct me if I'm wrong):</p>
  
  <ul>
  <li>A request token is issued (if my ConsumerKey and ConsumerSecret are ok).</li>
  <li>Then an authorization token is issued and the user is redirected to Twitter.</li>
  <li>The user authorizes my application. And an access token is issued.</li>
  <li>I get the current user's details and store them in the database (along with the access token).</li>
  </ul>
  
  <p>So far, so good.
  Now here is the confusing part. The user logs out. Then comes back and tries to authenticate with Twitter again. How do I determine his access token, If I can't get his identity before I have the access token ? I have him in the database, however I can't determine who he is, before he goes through the same steps all over again. I'm sure I'm missing something, and I'll appreciate it if you point it out. I'm aware of the IConsumerTokenManager, I tried reverse engineering the InMemoryTokenManager and see how it works, but it's still not clear.</p>