I agree! I love Ubuntu and dislike viruses and bad internet content. Ubuntu to my knowlage is not susceptible to viruses but if it was also able to filter bad internet content this OS would be amazing!
Hi, I'm rejecting this as a bug, usually the best thing to do for big features like this is to create a spec on https://blueprints.launchpad.net/distros/ubuntu so that it can be discussed with a number of developers..
In Edubuntu, we'll now include Gnome Nanny, it's available in the maverick archives now since last week. You can find more information on that here: http://www.tectonic.co.za/2010/06/gnome-nanny/
It's useful for small computer labs and home machines, unfortunately it doesn't do groups yet which doesn't make it particularly useful for larger installations.
Thanks for the idea,
I've unmarked this as security bug since it is more of a feature request, and made it public so others can see the issue too.