distributed server blacklist

i'm not really sure if this is the best newsgroup to ask this in or not
(if it isn't, what would be a more appropriate ng?), but anyway...

i'm considering making a php script i'm working on submit open http
proxies it discovers to a server blacklist. the only question is,
which one? a cursory search has revealed six, thus far:

http://www.agk.nnov.ru/drbl/
http://psbl.surriel.com/
http://opm.blitzed.org/
http://www.spamcop.net/
http://www.five-ten-sg.com/blackhole.php
http://dsbl.org/

i guess i could submit to all of them, but as the mail has to be
formated differently for each one (or atleast the ones i checked), i'd
have to do an email one at a time. as such, it seems like submitting
to just one would be better, but... which one should i do?