ATI 9.11 driver & Ubuntu 9.10
Ubuntu does not install 3d graphics drivers by default. Such needs to be installed by the user. As I use an ATI GPU at this time, I will focus on that, but the Ubuntu commands are very similar, if not identical for a Nvidia GPU.
GPU - ATI HD4850
Monitor - Asus VW222U 22"
Operating System - Ubuntu 9.10
GPU - Graphics Processing Unit. This is your video card, also know as a graphics card.
ATI - one of two leading graphics cards makers, the other being Nvidia
driver - this is software made by ATI or Nvidia for their respective GPUs. These drivers are proprietary, closed source and support 3d. Open source drivers do not support 3d are are installed by default by Ubuntu.
3d - this is an effect produced by installing the respective proprietary drivers.
ATI Linux Driver Download - http://support.amd.com/us/gpudownload/Pages/index.aspx
At the time of writing, the ATI 9.11 3d driver does not work with Ubuntu 9.10. I do not know what the bug(s) are.
As such I will defer adding to this guide until the bug(s) are resolved.