I am testing Ubuntu 11.10 and one thing that I didn’t like is the left panel showing Places instead of tree.
Now, if you are like me and want to navigate using a tree panel, run the following command in the terminal.
gsettings set org.gnome.nautilus.window-state side-pane-view "tree"
If you want to change it using a graphical application, install dconf-tools, start dconf-editor and
navigate to org.gnome.nautilus.window-state, change the value of side-pane-view to “tree”.
Now your Nautilus will look like this:
PS.: Ubuntu 11.10 Oneiric Ocelot still in Alpha3, not recommended to be used in a production environment.