WP Sentry allows WordPress authors to grant access to individual private posts to users and groups of users.
This is a simple plugin to allow for access-restricted posting, allowing bloggers to discuss sensitive subjects without Google or the world finding the post.
After plugin activation, an administration panel is added to your "Users" and "Plugins" tabs, allowing you to create user groups and manage WP Sentry's other options. The creation of user groups is completely optional, although it does make things a little easier.
Also upon activation, a section is added to the post creation and editing screen. This section allows you to specify which users or groups have access to the post. Setting any access restrictions here forces the post to be listed as "private" in WordPress, so you don't have to worry about forgetting to hide a sensitive post.
Users may be members of multiple groups. Multiple groups and multiple individual users may be allowed to view each post. Overlaps are ignored -- if the user is a member of any group that is allowed to view the post, that user will be able to view it.