title: Setting a Session Variable in a Model
body: <p>With Rails 3, How can you set a session variable in a model</p>
  
  <pre><code>session[:cannot_reason] = "no such item"
  </code></pre>
  
  <p>I'd like to set the above in my user model. Right now I get this error:</p>
  
  <pre><code>undefined local variable or method `session' for #&lt;User:0x00000102eb9c38&gt;
  </code></pre>
  
  <p>Ideas? Thanks</p>