I just discovered how easy it is to set up some simple multitouch gestures with synaptics. I heard some rumors that you can have multitouch gestures with (nearly) every notebook touchpad you want, but I never tried until now.
(Images from http://www.hy-tech.de/)
I followed this tutorial, it's german but I think everyone will be able to find a tutorial in english. If not, just read the "man synaptics", you'll find the synaptics options for xorg.conf with good explanations.
What I don't like is: why hiding these things in xorg.conf? Its powerful but only for power-users. I think we should have this in mouse preferences to! (probably the feature does already exist, I don't have the latest version of gnome yet)
Fancy fancy :) Try it out...
UPDATE: With the new Xorg coming with Ubuntu 8.10 and others, the settings I talked of are banned from xorg.conf. Now hal is the part that controls these things. If you want to set up synaptics via hal, you have to put a *.fdi file under "/etc/hal/fdi/policy".
Bits and pieces about free software and various other things.