Chode I think you've just answered the economic crisis dude, that is a BOMB Idea! But what do you do about the sugar then? Shit just hit me... DUH, they've got sugar packs at the table!
So you're getting a free glass, water, AND sugar. All you really gotta buy is the koolaid mix.
Genius my friend.
I do similar at the movie theaters, I'm a slender guy so I can fit cans of bee... *SODA*... in my back pants pocket and then you don't have to spend 8 goddamn dollars on a drink at the food counter. Movies are a ripoff.