Fun stuff. I love filling up glasses with different amounts of water and creating different ones, intervals...
I used to play the bottles on the bar <yes, like Gin, Whiskey, whatever> when I bartended in the islands

, til the boss got mad one day when I broke a bottle and outlawed it. Then, after the customers kept still requesting it, he allowed it if they agreed to buy the bottle if I broke it. It ended up being quite lucrative for the bar, selling booze by the bottle sometimes instead of by the shot.
Sandra Bullock in "Miss Congeliality" plays some mean glasses by rubbing on the rims.