Use FBAutopost wrapper class to publish to the user's timeline (requires Facebook App approval).

gistfile1.php

<?php
  try {
    $fb = facebook_autopost();
    $fb
      ->setDestination('me')
      ->publish(array(
        'type' => 'status',
        'params' => array('message' => t('Hello world.')),
      ));
  }
  catch (ErrorException $e) {
    drupal_set_message($e->getMessage(), 'error');
  }
?>

This should call the factory function facebook_autopost() instead of instantiating FBAutopost directly.