Here's a quick guide i have written to re-compile with the elantech driver, i am still playing with the restricted drivers guide, but will post if i finish it.
I have modified the patch file using the 2.6.22.14 kernel
This is using the most recent kernel source (2.6.22.14):

1) ensure source is enabled in the repositories un-comment (remove #) from all deb-src lines in /etc/apt/sources.list

2) run the below to obtain the kernel source
sudo apt-get update
apt-get source linux-image-2.6.22-14-generic 

3) the next 2 steps ensures bash has the /bin/sh symbolic link, this is from the howtoforge link, so i just copied this.
sudo rm -f /bin/sh
sudo ln -s /bin/bash /bin/sh

4) install required packages for kernel compilation
sudo apt-get install kernel-package libncurses5-dev fakeroot wget bzip2

5) i have modified the patch to support 2.6.22-14-generic, to apply it to the source:
cd linux-source-2.6.22-2.6.22
patch -p1 --dry-run < /where/you/saved/elantech-2.6.22-14-generic.patch

6) --dry-run does a dummy run of what it will change, nothing is actually changed
verify the output says:
patching file Documentation/input/elantech.txt
patching file drivers/input/mouse/elantech.c
patching file drivers/input/mouse/elantech.h
patching file drivers/input/mouse/Kconfig
patching file drivers/input/mouse/Makefile
patching file drivers/input/mouse/psmouse-base.c
patching file drivers/input/mouse/psmouse.h

7) if so, run:
patch -p1 < /where/you/saved/elantech-2.6.22-14-generic.patch

8) copy the current ubuntu config:
cp /boot/config-`uname -r` ./.config

9) run the make menu:

make menuconfig

10) Go to Load an Alternate Configuration File and choose .config

11) Go to device drivers -> input device support -> mice
select elantech and press the Y key
go back to the main menu (tab onto exit 3 times)

12) select Save an Alternate Configuration File and choose .config

13) exit menuconfig (tab onto exit, press enter)

14) build the kernel (the second command can take a few hours depending on your machine)
make-kpkg clean
fakeroot make-kpkg --initrd --append-to-version=-custom kernel_image kernel_headers

15) 2 deb files are generated, the kernel and the kernel headers. you should now be able to install these

16 ) from a ubuntu wiki page i can't find the lnk to, if you want to ensure the ubuntu logo appears on boot:

echo vesafb | sudo tee -a /etc/initramfs-tools/modules
echo fbcon | sudo tee -a /etc/initramfs-tools/modules

17) reboot, press ESC at the grub screen and choose the newly installed kernel, because this guide didn't change anything with the version numbers, it has labeled it as 2.6.22.9-custom - this is because the source is just this version patched to 2.6.22.14

18) once booted, test the touchpad

19) to test absolute mode do the following in the sysfs directory (it think this means /sys, it was on arjan's website):
sudo echo -n 0x16 > reg_10

And that's it, as said, i am still working on the restricted drivers guide, if you can't be bothered to do the above and have some decent web hosting i can upload the deb files i have generated let me know. The files are around 300mb due to the debug options being enabled (default ubuntu .config setting i believe)