S Hetjens

This plug-in restricts access to blog and feed. All anonymous visitors will be forwarded to the login page of WordPress 
before accessing the blog content. If access is restricted, rss and atom feeds will be disabled, too.
The feed can be activated as a private feed for each user. Every user will have a unique feed url to access it. That 
url is based on the username and an md5 hash of the hashed password stored in database. This plug-in will modify all 
by wordpress inserted feed urls to the user specific ones. But be carefull. If you content is confidential you should 
not activate the feed. There is no way to check which services are reading (and maybe publishing) the feed’s content.

Hetjens Registered Only

This plug-in restricts the access to blog and feed. Visitors need to login before accessing the blog. It offers a private feed for every user.

blackc2004

New Features: 
* 1.5 – Allows all users who are logged in to see all Private posts 
* show_private_posts() is now a widget 
* Merged with Partial Private Post (See below)
This plugin is a full featured private post management interface. It allows you to manage all private post’s publishing status via the “Manage” admin menu. It also provides the function “show_private_posts()” which can be used on the main page to list recent private posts (This can be used as either a function call or a widget). It uses the option ‘posts_per_page’ to determine how many recent private posts to display.
<h3>Arbitrary section</h3>

PrivatePost

This plugin is a full featured private post management interface. It allows you to manage all private post's publishing status via the "Mana …

Hetjens Registered Only vs PrivatePost