Our team has a small Mac that we use to display an auto-refreshed web page, but it requires an authenticated user be logged into it.
So the question: how can we show the browser, but have the keyboard and mouse locked from any unauthorized access? Password unlock would be best, but forced log-out might be okay.
As a secondary question: if the current user were on vacation that day, how could another user log into the machine?
[Edit]
The machine will also be used for other things several per week: video conferencing, watching the occasional YouTube video, etc.
It's important that the keyboard and mouse can be used when the machine is "unlocked", and highly desirable that the unlocking can be done quickly (<30 seconds)