i teach in mm, but am impressed that my year 11's often work in inches, when they want material. i encourage multi-numeric techniques.
i love the way we're mean to be a decimal nation, yet we still sell copper pipes in inches for the guage, but metres for the length, we measure distance in miles and fuel economy in mpg, but buy our fuel in litres.
i love our quirky nations use of measurments.
does make me laugh, i remember hearing about a project with i think NASA building rocket parts in the uk. the brits were sending drawings in metric, but the yanks were building in imperial. apparently it was a monumental c0ck up that cost alot of moeny when they realsied the parts didn't fit