Stamp prices are going up soon, so it's not a bad time to stock up. Even though I only use one stamp a month (I don't understand why my biggest bill, a mortgage payment, can't be made online), I picked up some of their latest commemorative sheets, and one of them celebrates Chen-Shiung Wu, also known as "The First Lady of Physics" and the "Queen of Nuclear Physics."

She won the Wolf Prize (probably should have won a Nobel), contributed to the Manhattan Project, performed pioneering physics experiments, including confirmation of quantum entanglement, and was a trailblazer for women in science (often compared to Marie Curie).

There are also commemorative stamps for Bugs Bunny and Star Wars droids, but if you only buy one set, buy this one.