Well, I have a compact manual hand held linear Imperial-Metric conversion device that I clip on my belt.

At uni I discovered that being bi-system was all the rage and I can swing both ways depending on who is in the room.

No shit... one day, I saw a carpenter working out the equivalent of 1200mm to Imperial with a calculator and then using his tape measure to mark a cut... it was the same as my tape measure which I described above, having feets on one side and metres (yes, metREs) on t'other.

What really pisses me off is when I purchase lumber and find out it was milled in the US. A dressed US 2X4 is not the same size as a CDN 2X4 and it's nowt to do with the measurement systems. I learned long ago that my drawings had to spec the sizes of components and not ANY overall dimensions, even before "free trade".