I was looking at WF and was wondering if it would be best to use the StateMachine workflow to follow a users state. i.e. user is anonymous, user is known but not authenticated, user is known and authenticated.
would this be a good way to go about solving this regular issue?
In my experience, WF is far too heavyweight for any such use - it is too difficult to do simple things with it. It is useless for this scenario.
I'd certainly be interested in opposite experiences, though - has anyone successfully used WF on a small scale in a simple project? Workflows and state machines are integral parts of any logical business domain but I have never seen a straightforward implementation of WF or any other framework for it.
No, I think that it is completely inappropriate. Please see these questions for more info:
You might be interested in my SO answer regarding Stateless, a light weight .Net state machine. I have used this instead of WF and have implemented it in a web environment.