we bill in a variety of currencies so it helps to keep up on where things are moving, values of sales and goods/service purchased. when I am buying online or doing deals wtih content people throughout latin america. while they charge in USD I like to know what they are actually making locally too. Plus for personal reasons too, travel, buying stuff for friends, watching investments in a variety of countries, etc

Metric/Imperial - well it is everything, from recipes to construction, it always comes up. I was raised in metric and have no idea what 75 Fahrenheit is or is a recipe calls for 2 ounces of chocolate.