I recently upgraded both of my laptops (work and home) to Ubuntu 9.04 (Jaunty Jackalope). Both laptops are Dells, with Synaptic touchpads. The default installation enables tapping and scrolling via the touchpad. For me, both of these features get in the way, and I always turn them off.
In previous Ubuntu versions, this required editing xorg.conf and restarting X. In Jaunty, the default installation has a “Touchpad” tab on the System->Preferences->Mouse dialog that lets you configure the touchpad behavior. Nice!
Oh, and by the way, Jaunty has also disabled the Ctrl-Alt-Backspace key sequence for restarting X. To re-enable it, edit /etc/X11/xorg.conf, add the following, and then restart X (or log out and log back in).
# restore ctrl-alt-backspace restart of X server Section "ServerFlags" Option "DontZap" "false" EndSection