You can protect your local network from unwanted adult content by changing the DNS nameserver settings on your router to use the OpenDNS FamilyShield DNS servers. It’s a free service that blocks most adult content at the networking layer.
I have a Linksys WRT-54GL with DD-WRT installed. Here’s a good video that explains how to set up DNS servers on your DD-WRT. Add the Family Shield DNS servers under Settings->Basic Settings -> Network Address Server Settings (DHCP) Just make sure the first nameserver in your DD-WRT settings is your router’s IP address (e.g 192.168.0.1)
You can also add these DNS settings to your local /etc/resolv.conf on Linux or TCP-IP Settings on Windows.
The IP Addresses of the OpenDNS FamilyShiled nameservers is (in resolv.conf format):