Xfdashboard is a Gnome shell like dashboard for Xfce. For easy and quick access without typing in any command into a terminal a keyboard shortcut can be defined in Settings -> Keyboard, e.g. the key combination+ runs the command xfdashboard. It has several views which shows different elements like windows of currently running applications window list), application menu etc. You can switch between the views using the view selector.
WWW: http://goodies.xfce.org/projects/applications/xfdashboard/start