Here are notes of installing 0.4.6 on ubuntu 8.04 on 2 Nov 08
1.apt-get install wallpaper-tray
2.ln -s /usr/share/gnome/apps/Applications/wp_tray.desktop /usr/share/applications/
3.Configured ~./wallpapers as wallpaper directory
4.Set change to 120 mins.
5.Gnome Control Centre, Personal, Sessions, Add
Name: Start Wallpaper Tray
Comment: Starts Wallpaper Tray
No record of where steps 3 and 4 were done.
I didn't like Wallpaper Tray sitting in the Notification Area. Found it does not from version 5. Could not find a 5.x ubuntu package. Downloaded 5.5 source tarball but too many missing dependencies. Checked in case they are ready (with apt-show-versions -u) but not.
It's so much easier in Xfce which does not require any extra packages!