People have smoked weed at every single concert I've been to. Most times it's as casual as if it's a cigarette, but sometimes they crouch down and hit a pipe or something. Only once have I seen security do anything about it, and it was as involved as shining a light on the guy who was smoking and shaking his head. Weed and concerts go hand-in-hand. I wouldn't really worry about it, especially if it's standing room only... You should be able to get away with it no problem. And on the way to the concert, stop at a convenience store and grab one of those single Prime Time cigars, the ones that come in the plastic case. If it fits, put the blunt in the case and it's safe and inconspicuous.