Only for two weeks as part of our work experience program, back when I was in 8th grade. We got to do everything the regular employers were doing, so I guess it counts.
Yup, several famous people - Swedish and non-Swedish. The nicest ones? Robert Englund and Elijah Wood! But I haven't met anyone who was rude (even Britney Spears was nice), some were just more charming than others.