http://news.coinupdate.com/why-we-shoul ... materials/
"The National Association of Convenience Stores and the Walgreens drugstore chain have estimated that handling pennies adds 2 to 2.5 seconds per cash transaction. Assume that the average citizen makes one such transaction every day, and so wastes (to be conservative) 730 seconds a year. The median worker earns just over $36,000 a year, or about 0.5 cents per second, so futzing with pennies costs him $3.65 annually."