The opposite approach might be worth investigating, too. Ever since the
surbl.org blacklists came out I've been pondering adding surbl lookup to
squidguard. I doubt if I'll ever have the time to do it, alas.
This is a brilliant idea.
Are you active on the squid/squidGuard list or dev list? As a user of both squidGuard and SA, I can see how URL blacklist lookups would be of a great advantage.
Martin
