I am using OpenSUSE 12.2 with GNOME-Shell and was wondering how can I choose to login to gnome-panel instead for a particular session?
This is useful to me for instance if I'm on battery without a socket nearby and need to save power.

I know it is possibly to force the fallback mode through the settings but I would like to be able to choose at login the particular gnome session.
Currently the only session options are GNOME, IceWM and LWM, not being able to choose which gnome. gnome-session-fallback-session and gnome-panel are installed.

Is this possible and if so how?