I installed Bannerfilter today using the instructions in the tarball with some modifications.
1) I but the www stuff under my primary site in a dir called 'bannerfilter'. 'chown -R www:www /home/e-smith/files/primary/html/bannerfilter' plus 'chmod -R 444 /home/e-smith/files/primary/html/bannerfilter'
2) Put the rest in a dir called '/home/e-smith/files/bannerfilter' to have it backed up by backup to desktop.
3) Modified update.sh to use wget.
4) Copied the conf file to /etc and edited it to point at the right directory. Also added a line near the bottom: 'LOG = /var/log/bannerlog'
5) 'touch /var/log/bannerlog' and 'chmod 666 /var/log/bannerlog'
6) Added a single line to /etc/squid/squid.conf: 'redirect_program /home/e-smith/files/redirector.pl'
7) Restarted squid. (/etc/rc.d/init.d/squid restart )

Tested by going to a known bannersite. It worked - and the log showed what had been blocked and why.
9) Wrote a template like John's.
10) Wrote a simple script for weekly update using update.sh and put it in /etc/cron.weekly.
I think that's it. Several ways of going about it really.

(If I knew how to create RPMs I would give it a shot. Fairly simple package).
/Jens