Just thought I'd add this link: http://www.tweakguides.com/UT3_1.html
It might actually explain some things that go unexplained often... I hate changing settings without understanding what they do exactly.
There's also the Unreal Tournament 3 Tweaker ( UT3T ) : http://forums.epicgames.com/showthread.php?t=594723
and the UT3 Ini Tweak-O-Mat: http://www.utzone.de/include.php?path=content/download.php&amp;contentid=6480