Ayman

With this plugin you can time limite the users accounts registered on your website for a specific amount of time.
The status of each account is displayed in each user profile which includes: 
1. Account status 
* New User The user didn’t login since the plugin is activated 
* Activated The user has logined in and the account is not expired 
* Deactivated The account has reached the time limit 
2. Account activation date 
* 0 The user didn’t login since the plugin is activated 
3. Account expiry date 
* Will show the date on which the account will expier.
Any user with “edit_users” capability can activate and deactivate each user account by clicking on Activate/Deactivate links under each user.
In the options page you can: 
1. Specify the accounts time limit 
2. Insert a custom error message for expired accounts

Time Limited Account

With this plugin you can time limite the users accounts registered on your website for a specific amount of time.

Mads Phikamphon

Almost Users Only is a plugin that limits public access to your blog. Visitors that are not logged in can only view a specific public page. If they are trying to reach other pages they will automatically be redirected to the public page.
If a visitor is logged in, he can view all the pages/posts on the blog (just like if it were a normal WordPress installation).
The public page can for example be used to display information about the site and a guide to how visitors can get an account.
IMPORTANT: WordPress still publish RSS feeds, so posts can still be read that way. Pages should be save though.

Almost Users Only

If logged in, the visitor can view all the pages/posts on the blog. If not logged in, the visitor can only view a specific public page.

Time Limited Account vs Almost Users Only