How to create user only for wiki? Does anyone know how I would create a user, maybe by email address, that would only be able to access a specific wiki on lion server?

I'm trying to allow access for clients (not OS X clients) that are associated with a wiki for a project we are collaborating on.
In the OS X Server app interface. Under users you can select the user then click the button next to the plus button at the bottom and click Edit User Access to Services. Deselect everything and leave only Wiki.