[dwaite]

> The US customary units are pretty logical, they're just not powers of 10.

It somewhat slides off the cliff when you take into account the existences of the imperial ounce and the US food labelling ounce, though.

[klodolph]

The US uses the US customary units and metric, not the imperial units.

Not that it matters much, since the US customary ounce and the imperial ounce are the same mass. Maybe you're thinking of the fact that an imperial pint is different from a US customary pint?