Wallpaper changers on lxde or lubuntu are nice to have but tough to find, particularly if you are trying to stay lightweight. Usually wallpaper changers don't usually work because they aren't compatible with pcmanfm.
So after searching the Internet for quite some time and fiddling around I came up with a super easy, simple way to have a wallpaper changer on lxde / lubuntu without using any memory or complicated scripts or programs.
I tried the wallpaper changer called variety which i found on these forums... however it didn't work for me but also upon launch it was using about 40 megs of ram on my system just to change the wallpaper... not exactly lightweight, and it was always running in the background.
I've also looked at some scripts and while they do work they are more complicated then they need to be... although i will say that they usually provide some type of timer wallpaper change feature, which this solution does not... however you'll see it really doesn't matter.
Ok here we go.
First lets make a desktop icon.
To create a desktop icon right click on the desktop and create a blank file. Name the file whatever you want just end it with .desktop I usually name the icon randomwallpaper.desktop
Once the file is created right click on it and open it with leafpad.
Copy and paste the following code in it
Once the code is pasted close and save it.
Comment=Randomly change LXDE wallpaper.
Exec=bash -c 'pcmanfm -w "$(find ~/Pictures/Wallpapers -type f | shuf -n1)"'
Now I'm going to assume your new icon is on the desktop
We will place this icon in two place...
One in your autostart folder (which provide a random background on startup)
And the other one will go in your applications folder (which will provide access to it through your accessories menu.)
Open your terminal and enter these commands
cp randomdesktop.desktop ~/.config/autostart
sudo mv randomdesktop.desktop /usr/share/applications
Open up desktop session settings (preferences menu) and make sure the Random Desktop icon is checked if you want it to change your desktop background on startup.
Finally and important... create a folder named Wallpapers inside your Pictures folder and place your desktop backgrounds in there..
Now whenever your computer starts it changes the background and if you want to change it yourself you can select random wallpaper from the accessories menu and it will switch it instantly.
This is an excellent no memory usage, super easy wallpaper changer solution without involving complicated scripts or heavy programs.
CAUTION: This has only been test on Lubuntu 12.04
I will be providing a series of easy solutions and linking to them below
lxde simple weather
aero snap for lubuntu
expose feature for lubuntu