As I head into a fun-filled weekend of paper-grading, let me just leave you for now with a simple rule to promote global harmony and warm fuzzies:
If you are standing at a crosswalk, and a driver waves you across the street, don't DAWDLE! Don't stroll, plod, or shuffle! Stride with all deliberate speed to the opposite corner. Run if possible. Or at least trot. Unless you are walker-bound, there is no excuse for holding up the polite person who has tacitly agreed not to run you over any longer than is absolutely necessary!
And would it kill you to give a little "Thank-you" wave?