I am personalising my Gnome-Shell in Ubuntu 11.10
I would like to disable the feature to open the Gnome's Dashboard when I close the last Window in a Workspace.
Edit to clarify: The dashboard is available only in GNOME Shell. The dashboard opens if you press the windows key (aka SUPER) or if you move the mouse to the upper left corner. If you close the last window of a workspace, but there are open windows on other workspaces, the dashboard opens automatically. The latter behaviour is annoying if you do not want to use the dashboard to open new windows or to change workspace. There are many ways to to both (Gnome do, Docky, keyboard shortcuts, clicking on something on the desktop, ...).
Edit: There is a related Q&A, which was closed because the asked the same question for Mint: How can I prevent the activity view for opening when I close the last running app?