title: How not get current_user
body: <p>i'm breaking my head to get the user of this situation:</p>
  
  <p>a conversation model:</p>
  
  <pre><code>has_many :conversation_participants, :dependent =&gt; :destroy
    has_many :users,
      :through =&gt; :conversation_participants
    has_many :messages, :dependent =&gt; :destroy
    has_one :display_message,
      :class_name =&gt; 'Message',
      :order =&gt; 'created_at DESC'
  
    def participants(options={})
      if options[:not].is_a? User
        users - [options[:not]]
      else
        users
      end
    end
  </code></pre>
  
  <p>and conversation_participants:</p>
  
  <pre><code>belongs_to :user
  belongs_to :conversation
  attr_accessible :user_id
  </code></pre>
  
  <p>on a conversation helper:</p>
  
  <pre><code> def self_or_other
      @conversation.conversation_participants.find_by_user_id(:not =&gt; current_user)
    end
  </code></pre>
  
  <p>please, someone could clear me how to get the other user inside conversation_participants model?</p>