I'll just be a minute
One of my favorite things people do when they are stressing over getting a computer with access to the internet is tell you they'll only be on for a few minutes. It usually goes like this:
User: (out of breath or too loud but generally stressed) I need an internet computer!
Me: We're pretty busy, you'll have to make a reservation.
User: I only need it for about ten minutes. (looks at you expectantly).
Me: OK, I can show you how to make a reservation at the terminal behind you.