Although almost every single one of you have fantasized about doing it at some point -- especially on 24th Street, where for some inexplicable reason people ooze down the street like lava -- you rarely act upon it. A group of vile teens, however, did. It seems that the reason for last Sunday's brazen shooting death inside the Metreon was over an argument about walking too slow down an escalator. Really. The 15-year-old mental......