Basically I followed this guide.

Here are my steps:

Create a boot image on a USB Memory stick

• Download ubuntu-9.04-netbook-remix-i386.img
• Install imagewriter sudo apt-get install imagewriter
• Insert your USB Memory stick (a least 1GB, all data on the USB Memory stick will be deleted!!!)
• Run imagewriter and follow the instructions to write the image on the USB Memory

Install Ubuntu-9.04 Netbook remix on the Aspire One

• Enter F2 at boot and in the boot-menu select USB HDD as first boot choice
• Follow the normal Ubuntu installation procedure to install the OS. My model have a SSD (Solid State Disk)

Increase performance

After the vanilla installation I found my Aspire One very slow, especially the graphics. But there where a few tweaks that speeded up my machine so it boots faster and the flash movies in firefox runs without chopping.

• Add the argument " enable_mtrr_cleanup=1" at the end of the first row that's not commented out and starts with "kernel ..." in the file: /boot/grub/menu.lst
• Convert from ext3 to ext2 (only if you are using a SSD-model)
  • Boot from your USB Memory again ("live USB Memory mode")
  • Open a shell, and write:
  • sudo tune2fs -O ^has_journal /dev/sda1 (assuming your root partition on /dev/sda1)
  • sudo e2fsck -y /dev/sda1
  • mkdir /tmp/x
  • sudo mount -t ext2 /dev/sda1 /tmp/x
  • sudo vi /tmp/x/etc/fstab (and replace ext3 with ext2)
  • Reboot (and remove USB Memory)
• I also found this page and after reading through it I added the row echo "base=0x20000000 size=0x10000000 type=write-combining" > /proc/mtrr before the exit 0 in the file /etc/rc.local But for me this didn't enhance the performance that much