For a few months, I had a wonderful part time gig as a "door monitor." My job was to sit in a building just inside the door from 5-8, after the receptionists went home, and occasionally look up from my reading to let in people who knocked (usually fewer than five per day).
I could have been replaced by a buzzer. And I made more than minimum wage! (It was either eight or ten bucks an hour, I forget which.)