[cjfd]

  // Add a vertical scroll bar
  vScrollBar = new JScrollBar(JScrollBar.VERTICAL);
  add(vScrollBar, BorderLayout.EAST);

This actually is helpful if a somewhat long list of components is being added. It makes it easier to find ones way in that list. Kind of like an index. So it really is not a useless comment.

But there actually are useless comments. Like when people are told to explain every class member and one ends up with

DatabaseConnection conn; // connection to the database

This really is just clutter and the next problem is that it needs to be updated alongside the code. I once had a colleague advocating adding a comment for every parameter that a method has and then he would himself not update these if parameters were removed. That really is not very good.