I have a Drupal site and a number of Mailman lists (cPanel flavor) on the same server and would like to set things up so users can subscribe/unsubscribe and manage their subscriptions via the Drupal site.

There appears to be an appropriate set of Drupal modules for that: http://drupal.org/project/mailman_manager http://drupal.org/node/195527 (user mailman register) http://drupal.org/project/mailman_groups (maybe)

Can anyone out there vouch for them, or warn me away from them, or suggest a better alternative?

The main user complaint I want to deal with is the fact that they now have separate logins and passwords for the two systems. I also want to use Drupal organic groups as the list archives, which I think I can do by having a Drupal mailhandler mailbox subscribed to the lists. Not sure how I will restrict access to the archives, however. Advice welcome on that too.