In Windows you'd hit Windows-L, which would take you to the login screen, and then they'd click "Guest" (or whatever alternate login you've set up). You'd still be logged in, and when they were done (or were giving it back to you for five minutes) you press Windows-L again and choose your own login to switch back to your still-running programs.
I'd be astounding if Linux didn't have an equivalent.
In Windows you'd hit Windows-L, which would take you to the login screen, and then they'd click "Guest" (or whatever alternate login you've set up). You'd still be logged in, and when they were done (or were giving it back to you for five minutes) you press Windows-L again and choose your own login to switch back to your still-running programs.
I'd be astounding if Linux didn't have an equivalent.