As of November 2005, ATI provides usable, properly packaged drivers which can be used on Ubuntu. They can even be installed easily!
1.
Download the apropiate drivers from [WWW] ati.com. You will need the ATI Driver Installer, not the seperate XFree86/X.org rpm packages. Save the installer into an empty directory (or at least one containing no *.deb files), since it will create several new files. 2.
Make sure the universe section of the Ubuntu repositories is enabled (See the AddingRepositoriesHowto) 3.
Perform the following commands (where <version> is the version number of the installer):
sudo apt-get install fakeroot gcc-3.4 module-assistant build-essential debhelper
fakeroot sh ./ati-driver-installer-<version>.run --buildpkg Ubuntu/dapper
If you run Breezy, replace "dapper" above with "breezy". This will create a number of .deb files in the current directory.
sudo dpkg -i *.deb sudo module-assistant prepare,update sudo module-assistant build,install fglrx-kernel sudo depmod
You need to repeat last step - building kernel modules - everytime you upgrade kernel.