John W. Poole/NPR

Teacher Rebecca Kayes shows off the dollar coins she uses in Quito, Ecuador. Rebecca Kayes hide caption

itoggle caption Rebecca Kayes

Jane Liaw Liaw orders coins from the U.S. Mint to earn frequent-flier miles. Jane Liaw hide caption

itoggle caption Jane Liaw

Millions of dollars worth of $1 coins languish in a vault at the Federal Reserve Bank of Richmond's Baltimore branch. John W. Poole/NPR hide caption

itoggle caption John W. Poole/NPR