PRINCETON, New Jersey -- If you were to walk along the streets of your neighborhood with your face up and an open expression, how many of those who passed you would smile, or greet you in some way?

Smiling is a universal human practice, although readiness to smile at strangers varies according to culture. In Australia, where being open and friendly to strangers is not unusual, the city of Port Phillip, an area covering some of the bay-side suburbs of Melbourne, has been using volunteers to find out how often people smile at those who pass them in the street. It then put up signs that look like speed limits, but tell pedestrians that they are in, for example, a "10 Smiles Per Hour Zone."

Frivolous nonsense? A waste of taxpayers' money? Mayor Janet Bolitho says that putting up the signs is an attempt to encourage people to smile or say "G'day" -- the standard Australian greeting -- to both neighbors and strangers as they stroll down the street. Smiling, she adds, encourages people to feel more connected with each other and safer, so it reduces fear of crime -- an important element in the quality of life of many neighborhoods.