After a week of using sbl.spamhaus.org and bl.spamcop.net as realtime blackholes via CommuniGate, prevented around 50 msgs/day from getting through to user accounts without a single false positive. Had been worried about false positives, but feel good about this. Still letting 10-20% of spam through though, so still want to set up SpamAssassin when time allows.
Music: Delroy Wilson :: Better Must Come