Well, just to update... Last night, I did a quick "Usher Orientation", authorizing them to eject people who couldn't behave. It turned out, however, that merely asking people to be quiet worked pretty well. Our only problem was the jerk with the laser pointer, and he was removed with little difficulty by one of our larger and more imposing looking ushers between acts. As to small children, the hard part is determining what sort of performance environment is appropriate. For instance, someone brought a three year old to The Crucible. This play really isn't appropriate for little kids...it's quite long and deals with difficult themes. However, some shorter concerts and such are good behavior training, as long as the kid has at least some degree of self-control.