Mollom provides a one stop solution for all spam problems and can protect the following Drupal forms. It offers and intelligently combines:

• CAPTCHAs -- both image and audio CAPTCHAs
• text analysis
• user reputations

and can:

Yet another node access module.

This module allows you to manage permissions for content types by role and author. It allows you to specifiy custom view, edit and delete permissions for each content type. Optionally you can enable per content access settings, so you can customize the access for each content node.

In particular:

This module is a little helper to maintain an administrator role which has all
available permissions. By default, Drupal only has one super user and this
module helps improve this drastically.

Documentation

Excellent tutorial provided by compujohnny:
http://www.jesox.com/posts/admin-role-module-preview

The ACL module, short for Access Control List, is an API for other modules to create lists of users and give them access to nodes. It has no UI of its own and will not do anything by itself; install this module only if some other module tells you to.

We're aware of the following modules using ACL (let us know if you know of others):

#D7CX: I pledge that LoginToboggan will have a full Drupal 7 release on the day that Drupal 7 is released.

The Login Toboggan module offers several modifications of the Drupal login system in an external module by offering the following features and usability improvements:

A CAPTCHA is a challenge-response test most often placed within web forms to determine whether the user is human. The purpose of CAPTCHA is to block form submissions by spambots, which are automated scripts that post spam content everywhere they can. The CAPTCHA module provides this feature to virtually any user facing web form on a Drupal site.

A CAPTCHA is a challenge-response test most often placed within web forms to determine whether the user is human. The purpose of CAPTCHA is to block form submissions by spambots, which are automated scripts that post spam content everywhere they can.