End the wasteful production of the penny (1 cent).
Currently, it costs 1.83 cents to make one penny. Pennies are rarely used by customers or put back into commerce. They are a nuisance that is collected in ashtrays, jars and fountains. Save money, round cash transactions to the nearest nickel (5 cents), like several developed countries.
Get rid of the one dollar bill and promote the dollar coin.
With the penny gone, dollar coins have a spot in cash registers and merchants do not have to invest in any changes. Customers who hate change and like bills will be delighted to know that the two dollar bill (which can take the one dollar bill's slot) means they will only ever get a single dollar coin per transaction. It also saves money by eliminating the storing costs of dollar coins.