Here's a stack of modules that I like which help a non-administrator manage their own users.
Administer Users By Role: http://drupal.org/project/administerusersbyrole
Role Delegation: http://drupal.org/project/role_delegation
Login One Time: http://drupal.org/project/login_one_time
No Current Password: http://drupal.org/project/nocurrent_pass
Once installed and enabled, I create a role ("site-owner" for example) and assign it the various permissions.
A few more little tricks and now the Site-Owner can create or cancel users, assign various roles, and send them a One Time Login link if needed.
One caveat I need to investigate...the Administrators (e.g., User 1) are still shown on the list of users (admin/people) and certain roles can be added or removed, but the Administrator role can't be removed and the Admin account can't be edited or canceled. Really the Site Owner can't do anything harmful to the Admin, but I'd prefer that account wasn't shown at all in the list. I need a module that will only show the users whose role is less than or equal to the current role.
