The Australian Government's NetAlert is offering every Australian FREE filters to protect children from visiting websites that are on a "white-list" (namely porn, newsgroups etc.)
You have a choice of either Optenet Web Filter PC 9.6 OR Safe Eyes (available for PC and Apple Mac) & you can download the filter or request a FREE CD-ROM of either filter.
Looks like government's 84 million dollar project on Internet content filtering is not as good as it seems. Just read this article on ABC News:
Teen hacks 'useless' Govt porn filter
I guess when it says "children" it means pre-teens. However you never know how computer-savvy kids are these days. A determined kid can circumvent parents' "filtering technology" anyway, and passes on the trick to all his/her mates at school.