Control Your Children's Internet Access with Gnome Nanny in Ubuntu / Debian

Gnome Nanny is a parental control system. By using Gnome Nanny you can easily  control what your kids are doing in the computer. You can limit how much time a day each one of them is browsing the web, chatting or doing email. You can also decide at which times of the day they can do this things. Gnome Nanny filters what web pages are seen by each user, so you can block all undesirable webs and have your kids enjoy the internet with ease of mind, no more worries! You can download a black list of sites from here

for ubuntu users ppa archive available here
$ sudo add-apt-repository ppa:guadalinex-members/ppa
$sudo apt-get update

Or You can install through synaptic package manager