The other day a woman passed me on the sidewalk and right by my ear she said, "I love you. Be careful." which I knew was addressed to someone on her cell phone, but it was live and sincere and physically quite close. Cell phones have increased the loud and clear friendliness and love on the sidewalk.

People walking next each other usualy wouldn't say such things so loud--at a normal conversational tone plus a little. It's good to have more of that in urban walking land to go with the barely missing each other bumper cars stuff.