How about something like this
<?
$ip = $_SERVER['REMOTE_ADDR'];
$bannedIp = array("ip 1", "ip 2", "ip 3", "etcetera");
if(in_array($ip, $bannedIp)){
exit("Your IP is not my favourite");
}
else{
?>
HTML code goes here
<?
} // end else
?>
Put that as an include file on top of your pages, or the full code.
Im not that experienced myself but what do you think?
Regards
/N