Stable Tag 0.3 Custom Post Type Privacy allows WordPress authors to grant access to users and groups of users across all posts, pages and custom post
This is a simple plugin to allow for restricting access to content.
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.