Help with spammers/bots

I got a dedicated server from OVH .. and few sites hosted there..
What I have notices for the last few days is increased load on the server and registrations on the web sites from spammers.. A lot..
I am looking for way to block these .. something like dynamic list of updated IP's which after that are blocked with IP tables or CSF firewall rules..
I found this : http://www.zoobey.com/index.php/resources/all-articles-list/417-spam-reduction-using-spamhausorg-and-iptables which is exactly what I am after .. but the spamhous web site seems to be down for the last few days .. So its not really usable..
Any ideas how I can make something like this working..
Thanks a lot