Gnome Lockdown

Setting the number of workspaces

gconftool-2 --direct \
--config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory --type int \
--set /apps/metacity/general/num_workspaces 1

Disable DPMS

gconftool-2 --direct \
--config-source xml:readwrite:/etc/gconf/gconf.xml.defaults --type int \
--set /apps/gnome-power-manager/timeout/sleep_display_ac 0

Disable Lock Screen

gconftool-2 --direct \
--config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory --type boolean \
--set /desktop/gnome/lockdown/disable_lock_screen True

Set Global Background Image

gconftool-2 --direct \
--config-source xml:readwrite:/etc/opt/gnome/gconf/gconf.xml.mandatory \
--type string --set /desktop/gnome/background/picture_filename /usr/share/wallpapers/default-1600x1200.jpg