Hi Sean,
You can use RBL's with Weasel, I use :-
rbl.comkal.net (internal only, includes all of China, and a couple of other countries).
zen.spamhaus.org
safe.dnsbl.sorbs.net
bl.spamcop.net
You can also use the following ones if you like :-
combined.rbl.msrbl.net
combined.njabl.org
dnsbl-2.uceprotect.net
I have rbl.comkal.net first to check as I host my own DNS, which is how I setup the rbl.comkal.net zone file.
I also use the "Banned" tab to add various domains.
In the filtering section I use multifilter, that calls ClamAV, and Weasel Filter.
ClamAV is setup here to dump scam and picture spam etc as well as virus's.
You can also join the Weasel mailing list via
http://www.os2voice.org/mailinglists.phpCheers
Ian Manners