Saturday morning in the village, people are out with coffee and tote bags, and the trucks going by get a wave whether the driver knows you or not. NICK'S SERVICE WITH A SMILE INC. runs on that neighborliness: mowing, edging, trimming and seasonal cleanups spring through fall, plowing and shoveling once the Southtowns go white. A cut lawn and an open driveway are practical things, but they also say plainly that somebody was here and somebody cared. That is the note this outfit tries to leave behind at every stop. Orchard Park, Hamburg, Elma and East Aurora all hear it.