Linux + Gnome + Bash = Random Background

Elso:

#!/bin/bash
files=(/usr/lib/xscreensaver/*) 
# Look for files in the XScreensaver folder 
n=${#files[@]} 
# For aesthetics 
"${files[RANDOM % n]}" -root & 
# Choose a random screensaver and execute it in the root window.

Masodik:

#!/bin/bash
dipath="/media/Stuff/Pictures/Wallpapers"
dicount=`find "$dipath"|tr -d ' '|wc -w`
dilist=`find "$dipath" -printf "%p#"`
dinumber=`expr $RANDOM % $dicount`
difile=`echo $dilist|cut -d "#" -f $dinumber`
gconftool-2 -t "str" --set /desktop/gnome/background/picture_filename "$difile"