in reply to
using HTTP::PROXY instead of SQUID as a company firewall
The difficulty is not the configuring of squid or even HTTP::Proxy to filter out keywords or domains. Thats easy. The real problem is maintaining the restriction list. And that is a whole can of worms + nightmare all rolled into one. Even the professional companies, such as netnany, websense or secure computing don't allways get that right.
Remember that amateurs built Noah's Ark. Professionals built the Titanic.