Remote background

Greetings.

I am working with profiles, an i need set the backgronund from a
remote site. The backgronud  can change daily, i need know if this is
possible, some way for set the background from a remote site?, by
example, a URL, http://somesite.com/wallpaper1.png.

i am put in backgronund properties line (gconf2-tool) the url:
http://somesite.com/wallpaper1.png, but at moment of user login the
backgronud  is show for 2 or 3  seconds and soon this it disappears.

gconftool-2 -t str --set /desktop/gnome/background/ \
picture_filename "http://somesite.com/wallpaper1.png"



Some suggest?.