Restricting directory in Apache per logged in user

There's some great apache voodoo going on in this blog post. I'm going to basically be doing the same thing for a site I'm working on - which means no more editing custom basic auth blocks within the apache config - just create the user in LDAP and let the front-end developer create the matching directory with FTP.

My code snippet looks like this:

RewriteEngine On
# are they asking for a URL with thier username
RewriteCond %{REMOTE_USER} ^(.*)
RewriteCond %1:$1 !^([^:]+):\1$
# if not, send them there
RewriteRule /ldap-test/([^/]+) /ldap-test/%{REMOTE_USER}/ [R,L]

# is the directory there
RewriteCond /var/www/html/ldap-test/%{REMOTE_USER} !-d
# if not, send them off
RewriteRule /.* http://sorry.example.com/ [R,L]