From time to time it's necessary to block access to people from various parts of the website. Many people use the following method when developing a site and don't want others to see it.
You only need to replace the "xxx" with your actual IP number. You can find your IP number from sites like http://www.whatismyip.com
RewriteEngine on
RewriteCond %{REMOTE_ADDR} !^xxx\.xxx\.xxx\.xxx
RewriteCond %{REQUEST_URI} !/construction.html$ [NC]
RewriteCond %{REQUEST_URI} !\.(jpe?g?|png|gif|css)$ [NC]
RewriteRule .* /construction.html [R=302,L]
This can also be useful to block areas of your site such as an /admin or /wp-admin section to prevent any outside intrusion attempts.