I've been busy recently writing sample applications that use Windows Azure Service Bus and Windows Azure web roles and Windows Azure (damn I'm tired of typing brand names now) Access Control Service namespaces. And each time I do, I create a new namespace and often I reuse namespaces for general services in what used to be called AppFabric -- the Service Bus, Access Control, and Caching.
If I'm creating a set of applications, and all I need is access control to that application, I'll need to use an ACS namespace to configure that application as a relying party (which I would call a relying or dependent application, but I don't write the names). But do I use an ACS namespace that is already in use? Do I create a new ACS namespace just for that application? Or are there categories of people or clients that I can group into an ACS namespace, trusted by one or more applications LIKE those used by those people or clients?
I'm curious what you do, but I'm doing more work figuring out the best way to go here from the perspective of the real world. More soon.