Simple Access Control is a WordPress plugin by pkwooster that allows authors to restrict the users’s access to individual pages, posts and menu items based on the user’s logged in status.
Features for Authors
You can lock pages and posts while editing by using the “Simple Access Control” widget.
You can set the message displayed when a visitor accesses a locked page using the “Simple Access Control” item in the Settings menu
The locked status is shown in the admin page and post lists
Changes seen by users who are not logged in
Locked pages and posts are not displayed
Locked items are removed from standard and custom menus
A message asking you to log in is displayed if you access it directly using its address
There is no impact on logged in users
Additional Features
There are no additional features supported by Simple Access Control. The code is simple, small and well documented, so you can use it as a starting point for your own access control plugin.
Download: http://wordpress.org/extend/plugins/simple-access-control/