title: How to put application to background?
body: <p>How to put application (activity?) to background so it can work there?</p>
  
  <p><code>moveTaskToBack(true);</code> doesn't work. I have <code>android:noHistory="true"</code> and this code:</p>
  
  <pre><code>@Override
  public boolean onKeyDown(int keyCode, KeyEvent event) 
  {
      switch(keyCode)
      {
          case KeyEvent.KEYCODE_BACK:
              moveTaskToBack(true);
              return true;
      }
      return false;
  }
  </code></pre>
  
  <p>What is wrong? How to put application to background?</p>
  
  <p><strong>upd</strong>: or maybe I can use moveTaskToBack(true) only in root (MAIN, LAUNCHER) activity?</p>