When you are out walking do you smile and acknowledge ping pedestrians?

When I'm in my hometown, yes, I do. However, I've found from experience that if you do this in some of the big cities, you're setting yourself up for harment from panhandlers and people selling bootlegged DVD's and purses. I suppose my point is that you need to know your surroundings before you decide to smile at all the folks you meet on the street.