Inline radio buttons

People seem to have trouble creating inline radio buttons on Drupal sites, so here's a quick demo that does it: http://aswapathy.com/d79de/irb

Here's the css (which resides in the irb.css file):

div.form-type-radio {
  display: inline;
  margin: 10px;
}

And here's the form (which resides in the irb.module file):

function irb($form, &$form_state) {
  $form['#attached']['css'] = array(
    drupal_get_path('module', 'irb') . '/irb.css',
  );
  $options = array(t('One'), t('Two'), t('Three'));
  $form['radios'] = array(
    '#type' => 'radios',
    '#options' => drupal_map_assoc($options),
  );
  $form['br'] = array(
    '#markup' => '<br />',
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit'),
  );
  return $form;
}