Rather than host all of these files myself, I've opted to provide the most useful links:

Video Card Drivers and Utilities:

Guru3d.com download section

I'm working with the Nvidia Forceware 169.09 Beta XP 32bit and having no problems. Newer drivers are available, but if it ain't broke, don't fix it.

Another important tool is the Guru 3D Driver Sweeper which I believe as instrumental in my success with UT3. Also available without the installer, just check higher in the directory tree.

UT3 Bonus Pack

A compilation of new maps from the creators of UT3.

Mirrors:

• Beyond Unreal
• Fileshack
• Gamespot
• Worthplaying

Direct X Updater

Download.Microsoft.com

If you don't have automatic updates enabled and you somehow didn't get updated by the UT installer, I guess you can try here.