Hi,
Having used Moodle extensively one of it's great features is the ability to "log in as..."
I'm currently in the process of implementing a single sign on solution and it's generally good, however: I still get a raft of calls about access.
As an admin it would be good to be able to log in as that person and check their access. As you can imagine: sometimes it's just user error, not access problems. A simple "login as" would stop a lot of emails and general admin problems.
If you've not seen the Moodle functionality - try it... it's the kind of thing that once you've seen it: you realise you can't live without it! :)
Cheers
Rick