Disable mouse acceleration Is there any way to disable mouse acceleration on a mac?

Mouse acceleration is what causes the mouse to move slowly when moving it a tiny bit, and a farther distance when moved fast. In other words, I want the mouse to always move the same distance no matter the speed I use.

I'm using a trackpad, by the way.

To understand what I mean by mouse acceleration, try this: 


Place your finger on the left most side of the trackpad.
Very slowly, move your finger all the way to the right of the trackpad, and observe that the cursor doesn't move very much on the screen.
Now try the same thing, but this time move your finger really fast from one side of the trackpad to the other. You should see that the cursor has moved a significant amount of distance more than it did previously, even though your finger traveled the same distance.
As far as I know, there is no way to do this without external tools.

Usb Overdrive lets you do this http://www.usboverdrive.com/ and is what I use.

Steer mouse also has this setting. http://plentycom.jp/en/steermouse/  

Mouse Curves http://triq.net/articles/mouse-acceleration-preference-pane-mac-os-x  Has the advantage of being free, but Apple removing the acceleration API in 10.6 may have ramifications on its utility.