I recently bought a used IBM ThinkPad T40 and put Linux on it (Fedora, specifically). It’s the first Linux laptop I’ve had and so the first trackpad I have had to deal with outside of a Mac. I hate trackpad clicks as I find I accidentally click all sorts of things when that is enabled. If I want to click the button is right there, really, what’s the point? Anyway, to disable that annoyance edit xorg.conf and add this line to the Synaptics section:
Option "MaxTapTime" "0"
Then restart X. YMMV if your trackpad isn’t Synaptics based. You can look in /proc/bus/input/devices to find out.
Side note, all hardware on this laptop worked right from the install for both Fedora and Ubuntu.