So on SWFchan, they don't have voting systems, but they do have an interesting tag system that both allows for exceptional content to be marked as such, as well as discourages some abuse.
I speak of course of the thebest and cool.
Anyone can easily rate something as cool and the site keeps track of how many cool rating its received.
the site also keeps track of the number of thebest a flash received however, in order to rate something as thebest you need to jump though some hoops
"You have selected "The best" as one of the categories to put this flash into. Because of this you
have to press the submit button 10 times with at least 1 second between each press (pressing too soon will lengthen the timer).
This requirement is here in order to reduce the number of flash files categorized as The best. If it is not worth 10 seconds of your life
it simply does not qualify as one of The best (you can instead put it in the Cool category if you wish). Times pressed: 0/10"

I would recommend a 6 rating tag system
pcool "public cool" anyone can rate it no time requirement
pthebest "public the best" anyone can rate it takes 10 seconds
ucool "user cool" must have an account to rate it
uthebest "user the best" must have an account and takes 10 seconds
thebest requires a user account to rate it as pthebest and uthebest as well as an additional 10 seconds
top all of the above plus 10 more seconds

This is all assuming the site can handle this kind of thing which I doubt it can.

Or
OR
oooor
Tag your fucking cards correctly. We've already had this discussion two months ago. You unique and speshul vote trolling ideas mean jack.
It means nothing.
It's useless, USELESS.
Rating cards based on opinions is stupid and USELESS.
Basing you opinions on the opinions of others is stupid in and of itself.

Tag your shit correctly and stop relying on other people to tag your shit for you. You may think your card is worth a million dollars, but others will see it as shit. If you're miffed at the idea of your card getting -1 or some other person getting a +1 from their own vote, you should shove your face into horse feces until the nutty bits end up going through your nose and riding your tongue out of your mouth.

Tag your shit and make your cards easy to find. If you don't tag it, then don't cry when no one cares.

Also, SWF chan uses the booru API but is not hosted by the standard booru servers which is why they have their own fancy tools.