You want people around you to argue? Start a conversation about tipping. A kid I knew would never tip waitress if his water glass was ever less than half-full, and the worst part was that he'd tell them that as we sat down. I assured the waitress that we'd like separate checks and I'd be tipping on my own so that I might avoid whatever it was they planned on doing to his food in the kitchen. Some friends always double the tax for the tip, some double the first number of the bill. Me? I always give 20%, except at airport bars. There's no way I'm giving some guy $2 for pouring me a $10 pint of Sam Adams. You have to draw a line in the sand somewhere.