title: order and limit with ActiveRecord sum?
body: <p>I have this ActiveRecord sum:</p>
  
  <pre><code>@websites = current_user.records.sum(:minutes, :group =&gt;'website', :conditions =&gt; "website IS NOT NULL")
  </code></pre>
  
  <p>I would like to limit it to the 10 highest minute sums.  Could someone let me know the syntax for that?</p>
  
  <p>Thanks in advance.</p>