Here are 5 out of the many.. and i mean many wallpapers i downloaded from the gnome.org ftp server.
You can download and use the wallpapers as your login screen or as your wallpaper. To download wallapers from the gnome.org ftp server open a Terminal window (Applications->Accessories->Terminal) and create a directory called Wallpapers in your Home directory. To do this copy and paste the following line:
mkdir ~/Wallpapers
Then connect to the gnome.ftp.org server copy and paste the following line:
ftp ftp.gnome.org
When asked for a username type: anonymous and press enter when asked for the password.
To go to the wallpapers directory copy and paste the following line:
cd cd /pub/GNOME/teams/art.gnome.org/backgrounds
Turn off promting, so asking you if you want to download each single file will not be asked. Copy and paste the following line:
prompt off
To download all 1280×1024 wallpapers type:
mget *1280×1024.jpg
Or download all .jpg wallpapers type:
mget *.jpg
Or download all .png wallpapers type:
mget *.png
Good luck and have fun!!