EU content filtering study
Just to place my 2 cent somewhere and not to spam the Content Filtering on CF bounty thread http://forum.pfsense.org/index.php/topic,2703.0.html
For home users using windows http://www.accessproxy.dk/ would work & it's free http://www.accessproxy.dk/ie/download/Brochure-us.pdf
In the EU supported study http://www.sip-bench.eu/sipbench.php?page=results2006&lang=en
i only found http://www.poesia-filter.org/ to be free for all.
I'm not completely sure of what's needed to make it work with pfSense. But i do think it's worth the consideration.