>Has anyone implemented an architecture for maintaining a logged-in user id in a Web App using Mere Mortals? I have created a class derived from mmUserManager which I could use to authenticate a user and store their Id as a property, but this does not work at a session-level - what I mean is that when I need to retrieve some data based on the user's id, that ID isn't stored in the Session or the Cache, or even in the ViewState of a page. This is a problem. Any suggestions?

Maybe I'm missing something in your question, but why don't you just store the user ID off in the session as soon as you've validated them? Then it'll be available when you need it.

Session["UserID"] = SomeVariableThatHasTheUserID;