Schneider Digital's driver is the one driver I haven't tried myself, but it seems like a serious attempt on making a decent ATI Radeon driver for Linux. Well, enough chatting, let's get down to business.
The installation instructions for this driver are exactly the same as for Section 2, “Alternative 2: Using ATI's own R200 Driver”, so follow those.
Congratulations, you are now up and running! Please let me know about your experiences with this driver, as I didn't try it myself.