Do I have 3D acceleration
 

So, I installed slack 10. ran xorgconfig. got xfce up and running. In Xorg.conf i uncommented Load "dri" and Load "glx". ran glxgears which worked well. Ran glxinfo which said direct rendering: yes
Can I now play for example UT2003 or windows games with wine or do i have to install something else?

processor: AMD Duron 1 Ghz
ram: 256 sdram
videocard: Ati radeon 8500
motherboard: Via kt133A
soundcard:Soundblaster 128 PCI

I have also agpgart module loaded.

Another question: in xfree86 site for radeon I should put Option "AGPMode" "4"
in my xorg.conf should I?

It does not hurt to try UT2004 or running games in WINE. For now, wait on including Option "AGPMode" "4" in your Xorg.conf until things are working. Usually I wait a week before tweaking my hardware. Do not expect games in Wine to be fast because Wine is a software emulator that creates some latency.