Oh I know how David feels. I myself have had instances where I forgot to turn down my sarcastic sense of humor and have actually hurt someone's feelings.
Gets exciting about 30 seconds in... This is a video of a Teslacoil which stands roughly 12-15 feet high. The sparks can easily get out past 20 feet. Up in the right corner of the screen you may see it arc to a fully extended fork lift.
