Menu item title callback for the 'user' path.
Anonymous users should see a title based on the requested page, but authenticated users are expected to see "My account".
function user_menu_title() {
  if (!user_is_logged_in()) {
    switch (current_path()) {
      case 'user':
      case 'user/login':
        return t('Log in');
      case 'user/register':
        return t('Create new account');
      case 'user/password':
        return t('Request new password');
      default:
        return t('User account');
    }
  }
  else {
    return t('My account');
  }
}