Show Me the (Great Women) on the Money! on the $20 Twenty

Here are some other candidates to be on the $20 bill, or other units of currency (almost all are Americans)

Vera Rubin, discovered Dark Matter
Edith Clarke, mathematician, electric power pioneer
Cecillia Payne, discovered how stars work
Annie Bell, compiled data for Cecillia Payne
Marie Tharp, discovered continental drift
Rosalind Franklin, x-ray crystalography critical to discovery of DNA
Grace Hopper, inventor of COBOL, computer science pioneer
Radia Perlman, RSTP, etc., "The mother of the Internet"
Bella Abzug, Mayor of New York
Golda Meir, 4th prime minister of Israel
Catherine the Great, architect of Modern Russia

Emmy Noether, the most important woman in mathematics (c.f., Einstein, et al), relation between conservation laws and symmetry and oh, so much more
Marie Curie, discoverer of radioactivity

Chien-Shiung Wu, "The Chinese Madame Curie," "Queen of Nuclear Research," "The First Lady of Physics." Using 1950s technology, found experimental proof that parity conservation does not hold in weak subatomic interactions (OMFG!! It's Higgs Boson, neutrino-level stuff! In circa Cultural Revolution China, in the middle of the boondocks!)
Lise Meitner, first to explain nuclear fission, 109th element "Meitnerium", director at Kaiser Wilhelm Institute
Murasaki Shikibu, authoress of the world's oldest novel, The Tale of Genji

So, for starters, the Internet, the world's most popular computing language (through the 90s anyway), some of the most important phenomena that make our world work which we didn't understand AT ALL before: continental drift, that stars are made of mostly hydrogen, how they work, etc., what radioactivity is, how nuclear fission works, what's weird about the weak nuclear force, the idea that fields and particles can produce our reality,  that we don't know what 95% of The Universe is made of, and what DNA is and how it's structured, and don't let's forget transmitting power over long distances with electricity, among many other things, were ALL the accomplishments of WOMEN. 

So how atoms and quantum physics work, how stars work, how our planet works, how the code that makes up all living things works, how computers and computer networks can be harnessed and used, how electricity can be harnessed and used. Major participation in politics, literature, and culture.

Thanks female gender! Thanks for your help on all that stuff! We'd hate to think where we'd be without all that.

I wrote another little piece on great women of our time.

Earlier version of this post.