Batching time/memory-consuming operations

Will need to look into batching time/memory-consuming operations, such as iterating over all nodes in the database.

The new batch API in D6 should take care of the node_access_rebuild() core function.

forum_access_form_submit() has the same problem, maybe there are more.

Additional information:
http://drupal.org/node/123705
http://drupal.org/node/108752
http://drupal.org/node/124727
http://drupal.org/node/127539 (batch API)
http://drupal.org/node/144337 (node_access_rebuild() using batch API)
http://drupal.org/node/169079 (batch API and .inc files)

D5 -> D6 update:
http://drupal.org/node/114774#node_access_enable
http://drupal.org/node/114774#node_access_rebuild_batch

node_access_example.module sample code and docs in http://cvs.drupal.org/viewvc.py/drupal/contributions/docs/developer/exam...

Additional TODO issues:
http://drupal.org/node/150106 (disabling ACL)
http://drupal.org/node/160358 (changing moderators in FA/IGA)

There seems to be no solution for Drupal 5...