Yay Korea! Table Buttons
My personal favorite is that when you're eating, your waiter or waitress leaves you alone. No awkward interruptions every five minutes to ask if you need anything. Instead, if you want something, you just push a button! It sets off a little tone (and sometimes a light) to alert the staff that you want something.
These little buttons are at the end of the table in almost every restaurant. It's so simple! No awkwardly flagging down a passing waiter or having him interrupt your meal. Push a button and your waiter/waitress comes right over! It's genius.