title: Xcode 4: How to open the currently-viewed file in the Assistant pane?
body: <p>I often want to edit in two different locations in the same source file. I miss the ability to drag a vertical split in an Xcode window; this feature was apparently lost when going from Xcode 3 to 4.</p>
  
  <p>Is there a super-quick way to open the currently-viewed file in the Assistant pane?</p>