[ryandrake]

> 2. Cost. There is a direct cost (like remarking everything), and indirect -- all the chaos and errors because of mixing up units. To foot the bill is hard sell in Congress.

Maybe for things like road signs where a lot of travel and labor would be required to change everything. But for most commercial products, you don't have to change everything all at once or make some kind of big retooling effort. Company would just have to pick a day, and from there on, instead of printing "16 fl. oz." just start printing "473 ml" on the package.

[acjacobson]

A lot of products already have both printed on the package.