We don't like censorship, but unfortunately it is mandated for K-12 schools and libraries by Federal law. Until that law is repealed, we are forced to either pay companies that are secretive about their blacklists, or use an open source alternative like squidGuard. This article talks about squidGuard installation and configuration.
http://networking.earthweb.com/netos/article/0,,12083_1371241,00.html
