Even better than the flask is PocketShots. They are exactly as they sound. A shot of alcohol in a small plastic pouch. You can put them in your pockets, bags or a ladyfriend's bra if security is really tight, and they won't feel it as they pat you down. Just gotta get a soft drink and you are good to go. Do it all the time for concerts, Cubs games, and any other event.
Pocket shots? Is that something you invented or are they actually sold somewhere?