We've made a list of the top SURBL DNS queries into my name server:

http://www.surbl.org/dns-queries.counts.txt

and a version with only whitelist hits:

http://www.surbl.org/dns-queries.whitelist.counts.txt

The sample size is somewhat small at 32k queries over the last 48 trailing hours, but it's still somewhat interesting. Specifically 2000 queries are sampled every 3 hours. (Please ignore some of the junk at the end of the unwhitelisted counts. That's stuff left over from DNS packets which I haven't cleaned out yet.)

I'm slightly surprised how high in the total rankings some spam domains are. That represents a huge amount of spam sent and blocked. :-)

Jeff C.