This blog is just a part of my website, the entire site is ~800 MB of [mostly garbage]. most of the other parts are blocked, due to both PHP restrictions and .htaccess – restrictions.
To block or allow a part of your site, .htaccess is a friend. It’s well proven and have been so for longer than you’d like to know 
PHP-blocking have had some problems over the years.
The creation of the .htaccess – file is really easy, here are a small sample allowing access from my host (and nowhere else):
order deny,allow allow from [my hosts IP pool]/[the netmask the host are using] deny from all
You get your hosts pool by first looking at the strange number you are told when going to whatismyip.org, dig the number with the command “dig 127.0.0.2″ (change 127.0.0.2 to the number given by whatismyip) – dig will get you the pool of IP-adresses your host are using for IPs like yours.