I don't mind giving tours. It's a great way to share with others this job we love (most of us anyways). I sometimes find them irritating when its a group of kids who are just too cool to be excited (even though you had been informed that they were super stoked to be there) and stand there like lumps and maybe ask about the microwave. However it can be very rewarding when it is a group of interested people who ask questions, listen, and are excited by what they see. Last week we had a group of kids, and one of them I am pretty sure will be one of us in 10 years.