This is really a function of the touch pad driver, in the case of my Lenovo W520 this is a Synaptics touch pad¹, see the man page² for more gory details. In my case I am running Red Hat Enterprise Linux 6.3 and the driver support was added in RHEL 6.2³, in this case just open the gpointing-device-setting⁴.

If you are not using RHEL then here is an example of some instructions here⁵, this is useful but without driver support from your touch pad you will need to edit your xorg.conf file manually and restart X everytime.

Reference: