When I wrote about my Shiny New Lenovo Ideapad S10-3s, I mentioned having various problems with the "buttonless touchpad". I now know that the device in question is actually a Synaptics ClickPad, which is a multi-touch enabled touchpad with integrated buttons.
The idea seems to be that it makes laptop/netbook design simpler and less expensive by eliminating the need for physical buttons. The implementation is, well, interesting. If I understand things correctly (feel free to correct me if I don't), the primary problem is that the entire surface of the ClickPad is touch-sensitive, so when you try to click one of the integrated "button" areas, it actually reads a touch first, and this interferes with it properly reading the button-click. Now, there is probably more to it than that, but I haven't torn one of these things apart yet, so I am not sure how they are physically constructed. It feels like there is actually only one physical "button" under the front edge of the ClickPad, so the device driver has to actually interpolate your finger position along with the click to decide if you are making a left, right or center button click.
In any case, however it works, or should work, the bottom line at the moment is that most Linux distributions still have difficulty with the ClickPad. There is quite a lot of discussion and work going on in developing and adapting the Synaptic driver to work properly with it. Oddly, it appears that it used to more-or-less work with older drivers - I've seen several comments saying that Ubuntu 10.04 worked with it, but 10.10 does not, for example. The results I have gotten so far are:
PCLinuxOS - works, including left/right buttons and tapping, but to actuate the buttons you have to touch only the very corners at the bottom of the ClickPad. In particular, if you try to click at the point where the "dot" for the buttons is marked on the ClickPad, it will not work. I believe that it works here because PCLinuxOS is still using a somewhat older version of X and synaptics, such as the version which worked on Ubuntu 10.04.
openSuSE 11.4 (factory) Build 989 - This is the absolute latest "daily build" of the next openSuSE release at this time, and HOORAY, the ClickPad buttons work. Both left and right, you can click them at the points indicated or within a much larger area around those points, and they work. I hope this means that the driver development has incorporated the necessary changes, so this will continue to work not only in further openSuSE builds, but also in the other Linux distributions as they incorporate the latest Synaptics drivers.
All Others (Ubuntu 10.10, Linux Mint 10, Fedora 14, Mandriva 2010.2, Jolicloud 1.1, Mint Debian, Pinguy) - at the very least, buttons don't work. Tapping will work for some of these, but on most of them it is disabled by default, so you have to manage to get logged in and get the mouse preferences program running in order to activate tapping.
There is one other piece of "interim" good news, if you already have one of these ClickPad units and you are struggling to use it. The situation most people seem to be able to get to is that tapping works for the left mouse button, but they can't get a right-click out of it. Take a look at Luis' Blog for an example of an xorg.conf file which will enable two-finger tapping to produce a right-click. You can copy the config example that he gives, and put nothing but that in the /etc/X11/xorg.conf file, and then logout, reboot, or just kill the X server. It works very nicely on every one of the systems listed above.