Module

Here's my module file:

    <?php


/**
 * Implements hook_menu().
 */

/**
 * Implements hook_menu_alter().
 */
function sparker_registration_menu_alter(&$items) {
  // Ctools registration wizard for standard registration.
  // Overrides default router item defined by core user module.
  $items['user/register']['page callback'] = array('sparker_registration_ctools_wizard');
  // Pass the "first" step key to start the form on step 1 if no step has been specified.
  $items['user/register']['page arguments'] = array('register');
  $items['user/register']['file path'] = drupal_get_path('module', 'sparker_registration');
  $items['user/register']['file'] = 'sparker_registration_ctools_wizard.inc';

  return $items;
}

/**
 * Implements hook_menu().
 */
function sparker_registration_menu() {
  $items['user/register/%'] = array(
    'title' => 'Create new account',
    'page callback' => 'sparker_registration_ctools_wizard',
    'page arguments' => array(2),
    'access callback' => 'sparker_registration_access',
    'access arguments' => array(2),
    'file' => 'sparker_registration_ctools_wizard.inc',
    'type' => MENU_CALLBACK,
  );

  return $items;
}


/**
 * Implements hook_form_FORM_ID_alter().
 */
function sparker_registration_form_user_register_alter(&$form, &$form_state, $form_id) {
  $form['#submit'] = array(
    'user_register_submit',
    'ctools_wizard_submit',
  );
}

/**
 * Implements hook_block_view().
 *
 * This hook generates the contents of the blocks themselves.
 */
function sparker_registration_block_view($delta = '') {
  switch ($delta) {
    case 'register_step1':
      $block['subject'] = 'Create an Account';
      $block['content'] = sparker_registration_block_contents($delta);
      break;
  }
  return $block;
}
/**
 * A module-defined block content function.
 */
function sparker_registration_block_contents($which_block) {
  global $user;
  $content = '';
  switch ($which_block) {
    case 'register_step1':
      if (!$user->uid) {
        module_load_include('inc', 'sparker_registration', 'sparker_registration_ctools_wizard');
        return sparker_registration_ctools_wizard('register');
      }
      break;
  }
}

?>