I've gotten my 580 GTX to work just fine with Ubuntu 12.10.
Go to Nvidia's website and download the right driver.
Once the file is finished downloading, set it to be executable.
Open up a terminal and do the following.
Insert this at the bottom.
sudo nano /etc/modprobe.d/blacklist.conf
Save and exit
blacklist amd76x_edac #this might not be required for x86 32 bit users.
Next type the following commands in terminal
Logout and at the login screen ctrl+shift+f1
sudo apt-get remove --purge nvidia*
sudo apt-get install build-essential
sudo apt-get install linux-headers-$(uname -r)
Log back in through the terminal
Navigate to your drivers and install by
sudo service stop lightdm
It will ask for user agreement say yes.
It will then say install script failed, click yes and continue
It should start installing kernel modules
Next it will have a few config screens just say yes to all