We just released our Asus Eee Gadget Model, where we also feature a free Wallpaper for download. Because it is not as easy to install a Wallpaper on the Asus Eee PC as it is on Windows or Apple computers here is a quick guide on how to do it.
Asus Eee Wallpaper Installation instructions for default Easy Mode Desktop:
1) Visit the I4U Gadget Model Wallpaper download page.

2) Click on the 800x448px Asus wallpaper

3) Right click on wallpaper image and Save Image As under the User folder

4) Launch the Terminal window with CTRL+ALT+T

5) If you are not logged in as Admin yet and have no admin password type:
sudo passwd
su (password of your choice)

6) Copy the I4U wallpaper into /opt/xandros/share/AsusLauncher folder
cp i4u_model_0408_800x448.jpg
/opt/xandros/share/AsusLauncher

7) Backup the wallpapers you want to replace.
cp business_internet_wallpaper.jpg business_internet_wallpaper-1.jpg

8)There are different themes business, home, student and accessability.
I have a Asus Eee 8G and I replaced the business_internet_wallpaper.jpg for instance with the I4U Asus Eee Wallpaper
cp i4u_model_0408_800x448.jpg business_internet_wallpaper.jpg

9) Done. When you now go back to the Desktop and switch between the Tabs your new sexy Dorothy Asus Eee Wallpaper appears.

If you run your Asus Eee in advanced mode you will anyway know how to set a wallpaper.
There is also a 800x480px version available on our wallpaper download page that also works on Windows XP running Asus Eee PC.