Ubuntu 12.04LTS and above by default runs their own instance of Dnsmasq via the NetworkManager service.
Install dnsmasq to cache DNS queries
sudo apt-get install dnsmasq
echo 'listen-address=127.0.0.1' >> /etc/dnsmasq.d/listen.conf
echo 'prepend domain-name-servers 127.0.0.1;' >> /etc/dhcp/dhclient.conf
service dnsmasq restart
Test with nslookup debian.org localhost