If you're doing 90 in the US, you're speeding; but if you're doing 90 in Italy, you're probably one of the slower drivers on the road. Of course, in the US, you would be driving at 90 miles an hour and in Italy at 90 kilometers an hour. Though most of the world uses the metric system of measurement, the US, Ireland and Great Britain are among the few that still use an imperial system of weights. Last month, the European Union reconsidered its demands that Britain and Ireland join the rest of Europe in measuring in meters. So, they may continue to sell milk in quarts, gasoline in gallons and cloth in yards.