On an average day, approximately 10 percent of the U.S. population eats at sit-down/family restaurants. In an average month, approximately 58 percent do so (Media Dynamics 2001). After completing their meals, almost all of these restaurant diners leave a voluntary gift of money (or tip) for the server who waited on them (Speer 1997). These tips, which amount to approximately $21 billion a year, are an important source of income for the nation’s two million waiters (Lynn 2003b). In fact, tips sometimes represent 100 percent of waiters’ take-home pay, because tax withholding eats up all of their hourly wages (Mason 2002).