Having stumbled on the new /etc/resolv.conf methods of Ubuntu 12.04 a number of times, I hope this is useful for you as well.
The contents of /etc/resolv.conf in Ubuntu are now controlled by “dns-nameservers #.#.#.#” in your /etc/network/interfaces file, like this:
# The primary network interface
iface eth0 inet static
dns-nameservers 18.104.22.168 22.214.171.124