code: public static Shell getActiveWorkbenchShell()
  	{
  		IWorkbenchWindow window = getActiveWorkbenchWindow();
  		if (window != null)
  		{
  			return window.getShell();
  		}
  		return null;
  	}
docs: Returns the active workbench shell or <code>null</code> if none
  
  @return the active workbench shell or <code>null</code> if none