The "fast" setting provided by mac os X is shown below:
<key>MouseScaling</key>
<string>5 2 2 3 6 4 10 5 15 6 22</string>
The format of the configuration string seems to be:
n t m {t m}
n = the number of pairs t m
t = a threshold.
m = a multiple
At least, that's my suspicion from the experiments that I've performed and the experience I've had previously. I have no idea what units these values are given in, and could easily be missing something.
Setting all the threshold values very high, should cause the mouse to behave more sluggishly. (it does). Increasing the multiples, on the other hand, should cause the mouse to move faster. (it does, usually)
It's possible to change this directly in the .GlobalPreferences.plist with your favorite editor. Log out, and log back in again and the changes will be in effect. They'll stay that way, unless you change the mouse settings though the control panel, in which case your changes will be overwritten.
The funny thing is that I _think_ I've succeeded in making my mouse go faster by changing the multiple values, but the change is either not nearly as dramatic as the numbers would suggest, or I'm just imagining that the mouse is going faster. I've been unable to perform a really convincing controlled experiment. It may be that the OS cuts of the multiple above a certain number and ignores anything that's higher.
Most recently I've tried:
<string>7 1 4 2 12 3 30 4 60 5 120 7 200 </string>
This seems to <i>feel</i> faster, but maybe I'm just imagining things, or maybe my mouse is so old that it just doesn't want to go any faster ;-)
Could someone else give this a try on their system and tell me what they observe?
-- ben