I know many of you have already seen this but I found it useful resources a check list of things just to run through to try and squeeze a little more performance out of my shoddy graphics card:

http://www.mesa3d.org/brianp/sig97/perfopt.htm

Yes, its old, but most of the areas still seem to apply if you're not using new hardware (i.e. you can't replace stuff with shaders)

Kev