UUID Computed Field for Drupal

gistfile1.php

<?php
/* Autopopulates a Drupal Computed Field [1] CCK field using the UUID module [2].
Requires the 6.x-1.x-dev version of the module UUID, with a specific patch [3].
It assumes that you only want to generate UUIDs once. It probably should be
abstracted into another CCK module, but I'm too lazy to do that at the moment.

[1] http://drupal.org/project/computed_field
[2] http://drupal.org/project/uuid
[3] http://drupal.org/node/502622#comment-1858190
*/

if (empty($node_field[0]['value'])) {
  $node_field[0]['value'] = uuid_uuid();
}