Ok - I didnt realize it was called workspace, but yes that is it.
But - what I want is a command line program that I can execute to show workspace 3. The sometime later execute a command line program to show workspace 1.
Sorry, I don't know about a command line option for this (and the documentation doesn't seem to mention one either). You could, as someone else suggested in an earlier response, send the simulated keyboard events to the right place, but that is rather kludgy. You may have better luck asking at http://gnomesupport.org/forums. May I ask why you are trying to do this? There may be a good reason not to provide command line support for something that switches the workspace the user is looking at.
Alfred