It seems a number of folks have been having problems finding touchpad drivers for Windows Vista. I recently started trying out Vista on a laptop at home which happens to have a Synaptics touchpad. Without the drivers and its enhancement programs, using the touchpad can be problematic. Eventually I found out that the latest Windows 2K/XP version of Synaptics' drivers from http://www.synaptics.com/support/drive.cfm works fine in Vista (at least on builds 5456+). Some of their older versions like the one that came with my laptop doesn't work in Vista but the on their site does, so perhaps they fixed the problems in the latest releases.
The other major touchpad vendor is Alps Electric. Unfortunately I cannot seem to find any publicly available driver downloads on their site. Hopefully their XP drivers also work on Vista. Anyone knows?
P.S. On build 5472 there is a bug in the built-in unzip which might cause problems with zipped downloads. Use a third party unzip tool like WinZip etc.