George Dumitrescu has released version 0.6 of his ‘Indicator Workspaces’ applet for Ubuntu 11.04 users.
The applet allows Ubuntu 11.04 users to customize the number of workspaces and rows used by the Unity ‘Workspace Switcher’, as well as switch between workspaces themselves directly from the panel.
Indicator Workspaces can be added via PPA(version 0.6 is Ubuntu 11.04 only; earlier versions available for Ubuntu 10.04 and 10.10)
Add ‘ppa:geod/ppa-geod’ to your Software Sources [How? See here], update and then search for ‘indicator workspaces’ in the Ubuntu Software Centre.
Alternatively download the .Deb package from launchpad.net/~geod/+archive/ppa-geod/+files/indicator-workspaces_0.6_all.deb, double clicking on the file to install.