Just to show that I have an open mind on measurement systems, I present http://www.whitechapel-ltd.com/hardware/bobsrule/bobsrule.shtml
As far as Metric goes, the first time I used it as a tool was making concrete takeoffs for a cost estimate on a Danish plant. My God, it was quick, as opposed to converting inches and fractions to decimals of feet, then dividing that by 27 to get cubic yards. Also, on another project, I was surprised to find out that a cubic meter of water weighed 1000kg!
As far as Metric goes, the first time I used it as a tool was making concrete takeoffs for a cost estimate on a Danish plant. My God, it was quick, as opposed to converting inches and fractions to decimals of feet, then dividing that by 27 to get cubic yards. Also, on another project, I was surprised to find out that a cubic meter of water weighed 1000kg!