Disable front end to use as CMS only?

To make sure only the front end redirects to domain.com, make a theme that uses the PHP header() function.

• Create a folder called redirect or
  something.

• Add two files to the
  folder: style.css and index.php
  (necessary for a valid WP theme)

• In style.css, add something like
  this:

  /*  
     Theme Name: Redirect  
     Description: Redirects the front end to domain.com  
  */
  

• In index.php add this:

  <?php
       header( "Location: http://domain.com" );
  ?>  
  

• Upload the folder to the themes directory and then activate it in the admin UI.