Absolutely,

An onload client script can accomplish the same thing. The script would be a whole set of conditions and setvisible's. One client script is probably more manageable than a pile of UI policies, though UI policies typically load faster.

It would look something like

function onLoad() {
   if (g_form.getValue('field1') == '')
  {
        g_form.setDisplay('field1', false);
  }
  else if (g_form.getValue('field2') == '')
  {
        g_form.setDisplay('field2', false);
  }
}