Change touchpad horizontal and vertical acceleration/sensitivity?

How do I individually change the horizontal and vertical acceleration of the cursor? I can scroll side-to-side in a single stroke on a 1600x900 monitor on my laptop, but I can never do that vertically. Furthermore, the touchpad seems to be too sensitive horizontally (I hold my index finger still, but the cursor subtly moves)... is this fixable?

I'm using a Synaptics touchpad.

Solution 1:

Solution for Ubuntu 11.04:

Add the options

Option "VertResolution" "75"
Option "HorizResolution" "75"

To the file /usr/share/X11/xorg.conf.d/50-synaptics.conf.

After doing that, mine looks like:

Section "InputClass"
    Identifier "touchpad catchall"
    Driver "synaptics"
    MatchIsTouchpad "on"
    MatchDevicePath "/dev/input/event*"
    Option "VertResolution" "75"
    Option "HorizResolution" "75"
EndSection

Now log off and log back in, and it should be fine! :)