As already mentionend in this blog, I use xfce4 with 10 different workspaces. Important applications run on dedicated workspaces, e.g. firefox on #3, emacs on #4 and so on.
You may switch from one workspace to another very conveniently by keyboard (per default e.g. for workspace #3).
There is one more configuration option, which is unfortunately off by default. You will find it in the xfce-config tools under “Detailed configuration of the window manager”. Select the tab Workspaces. There is a line reading similar to “Remember last workspace, use it again when changing via keyboard shortcuts”. If you check this, bring you to the workspace #n. Pressing the same shortcut again, it will you bring back where you came from.
IMHO very convenient.
Using a shell you may set this via xfconf-query:
xfconf-query -c xfwm4 -p /general/toggle_workspaces -s true