the name says it all, this little script will change the background of your desktop every 10 minutes. you just have to change the WPAPERS variable to match an existing directory full of jpg or png images. you'll have to have fbsetbg installed for this script to work..

wallpaper.sh

#!/bin/bash

WPAPERS="/home/danix/Immagini/natura"

while true; do
	find $WPAPERS -type f \( -name '*.jpg' -o -name '*.png' \) -print0 |
		shuf -n1 -z | xargs -0 fbsetbg -f
	sleep 10m
done