I haven't had to deal with a spammer in months, and my site gets a fair amount of traffic.
Someone here posted a link to this site a while back:
http://www.stopforumspam.com/On those rare occasions when I get a spammer, I report them. I use it more to screen new registrations. I have also found Googling email addresses to be useful. Sometimes Google picks up data from stopforumspan, and I can also see if the new registrant belongs to other forums or whatever.