Radeon HD 3870 + Xorg + Secondlife

Are there any options I can enable or disable in xorg.conf that would help SecondLife run better? Here's my current xorg.conf:

Section "ServerLayout"
Identifier "Default Layout"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
ModulePath "/usr/lib/xorg/modules"
EndSection

Section "Module"
Load "extmod"
Load "record"
Load "xtrap"
Load "dri"
Load "dbe"
Load "glx"
Load "GLcore"
Load "freetype"
EndSection

#Section "ServerFlags"
# Option "AIGLX" "on"
#EndSection

Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
Option "XkbModel" "pc105"
Option "XkbLayout" "us+inet"
EndSection

Section "Device"
Identifier "Videocard0"
Driver "fglrx"
Option "OpenGLOverlay" "off"
Option "VideoOverlay" "off"
Option "NoAccel" "False"
Option "EnablePageFlip" "on"
Option "XAANoOffscreenPixmaps" "on"
Option "TexturedVideo" "on"
# Option "Textured2D" "on"
Option "UseFastTLS" "2"
# Option "BackingStore" "on"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Videocard0"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection

Section "Extensions"
# Option "Composite" "Enable"
Option "XVideo" "On"
Option "RENDER" "Enable"
Option "DAMAGE" "Enable"
EndSection

Section "DRI"
Mode 0666
EndSection

"Better" is awfully qualitative, especially since we don't know what you're experiencing that's "bad" in the first place. Please expand a bit more; see http://www.catb.org/~esr/faqs/smart-questions.html#beprecise

I mostly meant in general improvements to performance, but if you want specifics, how would I improve the performance of shaders?

Increasing the fog factor should help (so you're not having to shade distant objects); but short of that, there's not really a good way to improve the performance of shaders beyond what you have now short of disabling shaders entirely.