Some people are really picky about their trackpads. [John] posted a guide on retrofitting a Synaptics pad in place of the newer, but less user friendly ALPS touchpad/stick combo used in the Dell Inspiron 8200. On the opposite end, [C. Järnåker], loves laptop keyboards enough to mod them for use on his desktop machine.
http://www.hackaday.com/2008/06/11/synaptics-trackpad-swap/