Did that a number of times. Was easier when it wasn't required after I was 12 or 14 or whatever the requirement was on Northwest at the time.
One time they asked me to walk down the aisle and hand out peanuts. A lot of people seemed to think that was totally cute. Seemed a little strange to me, but was more fun than sitting down and being bored. Was nice to be shown into the lounge area between connecting flights.
Unaccompanied flying is totally reasonable thing for children especially with the procedures airlines have in place for younger ones. Though it seems like airlines are making some of those procedures apply to older children now too, which is totally weird.