There is some sort of IP Denial for IP banning from sites?
Create a file named .htaccess
order allow, deny
allow from all
deny from 127.0.0.1
Just replace 127.0.0.1 with the IP
\o/ For help!!
if you just wanted to ban from a certain page or script you could also use PHP to get the IP adress.
$domain = GetHostByName($REMOTE_ADDR);
that will giv eyou teh IP Adress. You can compare it to a constant or banned users in a database or whatever.