I think we need to have a better way to separate true trolls (an admittedly loose category) from people who can be reasoned with and/or raise interesting points but are being down voted for other reasons (like poor grammar/writing). Once we have this we need to convince people to stop feeding the trolls. One way that I have seen proposed is tagged karma (eg +1 insightful -1 trolling). Additionally sockpuppets haven't been a major problem here, but given the role they tend to play in website decline we should have a strategy for dealing with them in advance.