For those who are concerned about the security of their PHP powered websites, do not forget to check http://php-ids.org/ . I found this website today and I am too a newbie to this.. Looks great.. Will try and post my feedbacks.
Meanwhile do check http://www.alt-php-faq.org/local/115/ which guides you to fight the spammers out. I had posted earlier regarding the same at Protect your Web Forms from email header injections , but here is the URL for the original article.