I made a handy chart

Clicky-clicky to download printable PDF.

What we need now is Volume-Mass conversions for common substances, i.e. what is the volume of 1 lb of dry black beans, etc.

By the way, the above chart makes the U.S. system look reasonably simple, but there are something like a million different definitions for, say, the ounce: fluid or dry, troy, tower, avoirdupois, apothecary, imperial, british, U.S., etc. Also I omitted cubic linear measure (i.e. cubic inches, acre-feet, etc), minims, drams, gills, fifths, pecks, bushels, fluid scruples (!), and fluid drachms from the conversion. I realize some of those are synonyms and some are not directly comparable, but do you know which? Don't tell me about the metric system; you'll be preaching to the choir.

On another note, I spent about 45 minutes today studying quantum mechanics, and then an hour making a chart showing how to convert cups into tablespoons.