Using a DisplayLink USB video adapter on Ubuntu 12.10
I just added "blacklist udl" to /etc/modprobe.d/blacklist-custom.conf
and commented out "blacklist udlfb" from /etc/modprobe.d/blacklist-framebuffer.conf
This was enough to get the monitor to display the green screen of success.
After that it's just a matter of setting up xorg.conf in the same way as previous Ubuntu versions.