Hi Mika,
There are several ways to block IP's from your server. It depends
on what type of hosting you have, the access you have, etc, etc.
It sounds like you got hit by a not too smart hitbotter which is good that makes it a bit easier. Drop me a mail at
[email protected] and give me some info about your host.
Things like do you have access to your apache config, do you have ssh access, is it shared hosting, can you use .htaccess
files, is it win or unix does it support perl or php?
I'll help you out one way or another :D
DynaMite