I have a Radeon Mobility 7500 in my ThinkPad R40. I tried using the fglrx drivers, but they don't support the card I have so it didn't work. As a half-solution I found that adding the following to my /ext/X11/xorg.conf increased my glxgears output from 610 FPS to 830 FPS. Nice and simple way to gain 35% performance boost!

Option "AGPMode" "4"
Option "AGPFastWrite" "True"
Option "EnablePageFlip" "True"

Note, you add the above to the video card's device section.