I would suggest that you use OpenDNS
http://www.opendns.com/solutions/household/Also consider creating a hosts file
http://www.mvps.org/winhelp2002/hosts.htmIf you really want to stop it, download a Linux LiveCD, confront the porn viewer, and tell him to use the LiveCD to boot into linux to view his porn.
How would that stop anything? Only "advantage" using a Linux Live CD in this context is that it will not leave any trace of the surfing history.