This is an update of v1.2 (I call it v1.3) of the Slideshow screenlet for Gnome/Compiz, originally written by Helder Whise and modified by David Lyons. It adds automatic rotation of images that are oriented left or right based on the images’ exif data.
git clone git://github.com/rizzlesauce/slideshow_screenlet.git ~/.screenlets/Slideshow/
sudo git clone git://github.com/rizzlesauce/slideshow_screenlet.git /usr/share/screenlets/Slideshow/