Acer Aspire Ubuntu
Installing Ubuntu-linux is fairly simple.
In this howto the Acer Aspire is used as an example....so some specific issues will be mentioned about this.
First you need to decide what desktop environment you would like to use:
* Ubuntu: Gnome desktop www.ubuntu.com
* Kubuntu: KDE desktop www.kubuntu.org
* Xubuntu: Xfce desktop www.xubuntu.org
(all 3 lead to a working linux.....it's just a matter of taste)
Go to the site containing the ubuntu you like and choose to download the latest version (9.04 .....for all 3 types...KDE, Gnome, Xfce).

As I'm an old school linux user I will use KDE for this howto.
For the Acer you need the 64bit version!
After downloading the iso burn it on a cd....and boot it (on the acer F12 menu....activated in the bios)
You might check the distro first by letting it boot to a live environment. Or install to a 4gb usb stick as I did in this example.
Choose to install (second option when the cd is booting up)
Walk through the forms you see.....about language's, keyboard layouts, time zone's etc.
On the last step you get the summary of the chosen options and you're almost ready.
The grub bootloader will be installed on the MBR of your harddisk by default (if osx installed: the osx bootloader will be erased)
Look under "advanced".....and choose where the bootloader needs to be placed if you dont want to mess with the MBR of the internal HD.
This could be done by installing grub to the boot partition of the linux installation (the partition where linux is installed on).
Or when installing on usb (like I did) ....grub on sda...(I just boot the usb-stick installation by using the F12 boot menu on the acer)
Next step is to push the install button and wait until it's all ready and installed.
After installation (you will be notified when ready)...the pc will reboot and boot the installation.
On the acer you will almost have an instant working environment....only wifi needs some minor attention.
Connect to the internet with a cable......and get the updates.

After this you check the hardware drivers and activate the fwcutter driver for wifi.
You might need to togle the wifi button. (next to the soundports on the front)

Finished.....all hardware working 100%

Boot isues:
Here are some workarounds for boot problems (OSX-Linux-windows-dual and triple boot)
Grub installs by default to the MBR and lets you choose between booting linux or xp/vista.
When OSX is installed the EFI-bootloader will be on the MBR (to choose booting osx or windows)
Grub does not pick up the OSX installation (when you installed that before)...and needs manual editing.
To make it easy, reinstall the EFI bootloader after installing linux (grub installed on the linux-bootpartition...not on the MBR) and all partitons will be available to boot again.
Thats why a typical triple boot installation should be performed in such order that OSX is last installed. (only the order....not the place on the HD)
Reinstalling the EFI bootloader:
Boot the dvd and uncheck all accept the EFI bootloader
In case you cannot boot the osx-10.5.4 dvd (leo4all) anymore.....use the howtoos cd to boot OSX on the hd (80 or 81 depending on what partition and without any parameters)....open the install dvd on the desktop and browse to:
System>Installation>Packages>EFI-Bootloader.pkg and install.
After this the new partions/installations will be on the bootmenu too.
Enjoy!