How to add user to some group during registration AUTOMATICALLY

I noticed that the 2 solutions referenced above use Rules, and are a bit messy. Here's a simpler solution in code I wrote that I think is a much neater approach. Obviously set $gid to the group you wish to add new users to:

/**
 * Submit callback for user_register form.
 */
function codify_user_register_submit($form, &$form_state) {
  global $user;

  // Automatically assign users to a particular group. 
  $gid = 1;
  $uid = $user->uid;

  $account = user_load($uid);
  $values = array(
      'entity_type' => 'user',
      'entity' => $account,
      'state' => OG_STATE_ACTIVE,
     );
  og_group('node', $gid, $values);

This was implemented in COD (in the Codify module, actually) for the first year of NYC Camp. In subsequent years, users can login with their existing accounts and self-register for a new annual event. That of course is slightly more complicated…