>>In your application you can simply store the UserID and Start time when you start and log the time when you exit. You can store this info in a table, then you would have all statistics available to you.
>
>That technique does not work 100% of the time. If the workstation crashes, your table will still show the user is logged in.

Good point. I'm sorry, forgot at this moment how we worked around this problem. I guess it's a known problem with known solutions.