We have turned the top 425 or so domains from Andy Warner's AbuseButler - Spamvertised Sites list:
http://spamvertised.abusebutler.com/
into a beta SURBL for testing:
ab.surbl.org
again this one is only hosted on a few name servers now so please don't use it for production yet. We'd like your feedback about performance, false positives, etc.
Andy's data is quite similar in principle to my SpamCop data in sc.surbl.org. His list is ranked by number of batched reports in a 7 day window, and he has various data sources.
I'm inviting Andy to discuss this further here.
Jeff C.