I run a PHPBB3 forum and recently fell victim to the usual spammy software that creates forum accounts (bypassing captcha) and spams the hell out of your forum.

While this does not really bother me too much it did in terms of bandwidth which costs me money.

I've now put in place .htaccess and php rules to deny tough and easy proxies from accessing my websites.

Has anyone else got any tips on how to reduce bandwidth and save money?