I have a 13“ MacBook Pro (7,1). You can find out which MacBook you have by running the following command under Ubuntu.
sudo dmidecode -s system-product-name
If you have the MacBook Pro 7,1 you'll also want to look at the official Ubuntu documentation for the Macbook pro.
This MacBook has an nVidia GeForce 320M GPU. You can install the latest version of the nVidia driver under Ubunto 11.10 Oneiric using the following commands.
sudo apt-add-repository ppa:ubuntu-x-swat/x-updates sudo apt-get update sudo apt-get install nvidia-current
This adds the ubuntu-x-swap PPA and installs the newest version from there.
I cannot boot kernels after 3.0.13 using this method. ActionParsnip on the #ubuntu IRC channel suggested that I uninstall nvidia-current and remove this unsupported PPA. Then boot the new kernel and install the supported one. I may try that and then reinstall everything if it doesn't work. It's probably time for a clean install anyway.