I installed from the default Ubuntu repos first by going to the software properties and installing Nvidia-Current. And reboot afterwards.
As that version was a bit outdated I ugraded it using the Ubuntu-X team PPA sudo apt-add-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get update
sudo apt-get install nvidia-current nvidia-settings
(or just do a dist upgrade)
A week later I upgraded it to 310.19 by downloading the driver and installing manually (ctrl+alt+f1 (which doesnt works for you?) -> login as root -> $ killall mdm
-> $ sh ./NVIDIA..
(This will ask you a few things, say yes for dkms and nvidia-settings) -> blacklist nouveau ($ nano /etc/modprobe.d/nvidia-graphics.conf
with this text in it:blacklist nouveau
. -> reboot
I got an Nvidia GTX 550 Ti as videocard
EDIT: fixed a typo at the blacklisting part