For bicycles, we still talk frame sizes in inches. A 26″ frame is the standard adult frame.

My granite countertops were purchased in inches. We call them 3/4″ or 1-1/4″ (the common size), even though they really are 20mm or 30mm respectively.

Luggage for US carriers on international flights are still expressed in pounds. It seems we all have 50 lb. weight limits.

I’ve never seen “mikrograms” but we use mg quite commonly for medications.

Just because a lot of the units are the same, I’d express doubt that either one is truly metric or not metric. They were simply added as part of the SI units because they’re natural units. A kilobyte is 1024 bytes, neither quantity being anything specifically “metric.” In fact the IEC’s been pushing for non-SI prefixes for these power-of-two measurements — kibi-, etc.

For the most part, the United States already *is* a metric country. Individuals choose to use fahrenheit, cookbooks use cups and ounces, and the road signs are in miles. It’s not really an issue, because virtually all professional work is done with SI units.

Oh, our surveying system in intimately tied to non-metric units. It would be fun in 300 years wondering why counties, townships, and plats are all these weird decimal numbers!