sidewalk etiquette
when caught behind someone who's walking slower than you want to be walking, general etiquette demands a deft and apologetic overtake, possibly with a polite murmur as you squeeze past. just for kicks, I sometimes like to walk right next to them. for some reason this is some sort of ghastly faux pas of a similarly towering magnitude to, say, making eye contact in a crowded elevator. people get edgy, and it takes less than five seconds for them to either slow down or speed up so that you're no longer walking in the same plane. try it, it's fun.