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
auto eth0
iface eth0 inet static
address 10.0.191.100
netmask 255.255.255.0
network 10.0.191.0
gateway 10.0.191.1
dns-nameservers 8.8.8.8 4.2.2.2