if you go to add/remove in ubuntu and search for content, you should find that ubuntu has added an internet content filter, I haven't been able to test it as I can't get ubuntu on my schools network. But anyone else could try it.
content filter in ubuntu 9.04 add/remove
Archived thread 1147709 from Ubuntu Christian Edition. Markdown source: Ubuntu_Christian_Edition/thread_1147709_content_filter_in_ubuntu_9.04_addremove.md
okay i did some checking and it seems the new content filter for ubuntu is a combonation of dansgaurdian and clamav.
edit: okay my bad, the one in add/remove is a gui for willowng, the willowng backend is in the package manager and so is dansguardian, but no gui for it and it requires squid.
Good one dude..keep doing nice work