But things are going easier for series Z owners, as there is an automated script now. Thanks ernolf !
The good practice is to use the VGN-Zseries-janitor script. It installs all the stuff correctly, and allows to switch between the nvidia and intel cards by using the slider (before the reboot). No hot switch for the moment, but that’s not a real issue. I heard there are some issues with a windows 7 dual boot, because of the bios upgrade needed (read this). But, actually, I’ve already upgraded my own BIOS (I know, I’m adventurous), and there were no problem with the script.

One thing I think the script doesn’t do (I guess, the explanation at the end of the script is not very clear), is to add this kernel instruction :

In /etc/default/grub :

RUB_CMDLINE_LINUX="acpi_osi=\\\"!Windows 2006\\\""

And then run sudo update-grub to create a new /boot/grub/grub.cfg

(In my install, there was already an empty instruction (RUB_CMDLINE_LINUX=”"), so I just filled it with the value (string acpi_osi=\\\”!Windows 2006\\\”)

(You also can do it at boot time by hitting the “e” key.)

An other thing I haven’t done/tested useful is to customize screnn config (xorg.conf or nvidia-settings), as they describe it :

“To make a complicated xorg.conf-file unnecessary (after nvidia installation is ready and everything is running well) one can use nvidia-settings as root (sudo nvidia-settings) or as normal user, make the settings you want and then save them in an rc-file. Now enter the path to this rc-file into /etc/default/switch-x-to”. You must save the file generated by nvidia-settings in /home/<username>/.nvidia-settings-rc, and uncomment the matching line in /etc/default/switch-x-to (change “<username” by your actual username of course) :
NVIDIASETTINGS_RC='/home/<username>/.nvidia-settings-rc'

Make a backup of this file, if it already exists (was the case for me).

Solution 2 : icedTea (seems to not work on all sites, especially logmein)
http://ubuntuforums.org/showthread.php?t=774956
(Install of 1.4.1 64 bit java plugin)
The easiest way to download OpenJDK and Icedtead (the plugin) is Applications > Add/Remove > Change the Show box to either “All OpenSource Applications” or “All Available Applications” (The former is also known as Universe and contains free (as in speech) applications, while the latter is also known as Multiverse and contains proprietary appliations.) > Search: Icedtea > click on the boxes next to OpenJDK and Icedtea > apply changes > apply > close.
——

1. Download : http://www.java.com/en/download/linux_manual.jsp -> linux self-extracting ( jre-1_6_0_02-linux-i586.bin)
2. sudo -i (to install in a system-wide location)
   
3. cd For example, cd /usr/java/ (or /opt/java or a home subdir)
   
4. Change the permission of the file you downloaded to be executable. Type:
   chmod a+x jre-6u-linux-i586.bin
5. Verify that you have permission to execute the file. Type:
   ls -l

1. Start the installation process.Type:
   ./jre-6u-linux-i586.bin

This displays a binary license agreement. Read through the agreement. Press the spacebar to display the next page. At the end, enter yes to proceed with the installation.

1. Java is installed into its own directory. In this example, it is installed in the /usr/java/jre1.6.0_ directory. When the installation has completed, you will see the word Done.

1. Java is installed in jre1.6.0_ sub-directory under the current directory. In this case, Java is installed in the /usr/java/jre1.6.0_ directory. Verify that the jre1.6.0_ sub-directory is listed under the current directory. Type:
   ls

The installation is now complete. Skip to the Enable and Configure section.
Enable and configure

]]>

Commands :

xrandr to show all the available configs, where I can see that my second sreen  (on Iiyama ProLite E2607WS)  miss the correct resolution 1920×1200 (60hz).

So I must add the mode for xrandr :

1. Find the correct modLine to add :cvt 1920 1200 wich output
# 1920x1200 59.88 Hz (CVT 2.30MA) hsync: 74.56 kHz; pclk: 193.25 MHz
Modeline "1920x1200_60.00" 193.25 1920 2056 2256 2592 1200 1203 1209 1245 -hsync +vsync

2. Copy the second line without “Modeline” and Paste it in xrandr –newmode command :

   xrandr --newmode "1920x1200_60.00"  193.25  1920 2056 2256 2592  1200 1203 1209 1245 -hsync +vsync

3. Add this new mode to LVDS VGA output (you can see the correct name for resolution string with the command xrandr, without argument) :

   xrandr --addmode VGA 1920x1200_60.00

4. Tried without success  to do :

   xrandr --ouptut VGA --mode VGA 1920x1200_60.00

5. Finish the job with gui utility “screen resolution” (“System > preferences > Screen Resolution”)

NB. With my former monitor (a samsunc syncMaster 223BW), my second screen was flickering. It was du to noise in the ground wire of the installation. When I was disconnecting my laptop from AC power, the flickering was stopping (found the idea on the net after several hours searching for a software/driver problem…). So, I plugged the monitor on a 2 ground plug (you can use a 3 to 2 grounds adaptor), and the flickering was over.

This howto can be used for any screen/graphic card combination if your native screen resolution is missing.

https://secure.logmein.com/labs.asp

Edit : install icedTea / openJDK :

http://ubuntuforums.org/showthread.php?t=774956
The easiest way to download OpenJDK and Icedtead (the plugin) is Applications > Add/Remove > Change the Show box to either “All OpenSource Applications” or “All Available Applications” (The former is also known as Universe and contains free (as in speech) applications, while the latter is also known as Multiverse and contains proprietary appliations.) > Search: Icedtea > click on the boxes next to OpenJDK and Icedtea > apply changes > apply > close.

1) Install ia32-sun-java6-bin (with synaptic)

2) modify jre to load (zend support) in zend .ini file

Default zend ini file is : /usr/local/Zend/ZendStudioForEclipse-6.1.2/ZendStudio.ini. Add the following lines to the start of the file:

; Run Zend Studio with system's JRE
-vm
/usr/lib/jvm/ia32-java-6-sun-1.6.0.14/jre/lib/i386/client/libjvm.so
; ----------------------------------------

Of course, adapt you path to libjvm.so (in synaptics, properties of ia32-sun-java6-bin->files).

64 bits version of Zend Studio is planned, but with no ETA

This links were helpful for me :

• http://forums.zend.com/viewtopic.php?f=59&t=910
• http://ubuntuforums.org/showthread.php?t=553508
• http://www.dbaranski.net/node/17

NB. Install

In order to install  you must have libc6-i386 and ia32-libs. If not make this :
sudo apt-get install libc6-i386 ia32-libs
In my install of jaunty (9.04), il was already installed.
Thanks to Dominic for this tip.