[cnelson87]

Is there a way to temporarily "lock-up" my log-in so that I may safely walk away from my computer while running background tasks, and not have to worry about someone jumping on and interrupting a job-in-progress? I think windowz has something like that but I don't what they call it.

[Angus_D]

Turn on screensaver passwords, and set a hot corner. Then just shove your mouse into the hot corner when you walk away.

Or if you're on 10.3 you could turn on multiple users and switch back to the login window.