It's that time of winter when those who are tired of shoveling snow begin to dream of a sunny beach. A beach is a reminder that it takes very little to keep a child busy. Toddlers scream and jump with delight each time a wave rolls over their toes then recedes, leaving bubbles on the surface of the sand. There are birds to chase and never catch, horseshoe crabs and bits of flotsam to examine. A shovel and some plastic take-out containers are enough to keep Sand Architects building castles and fortifications until the tides change. I am a shell person, not knowledgeable, but always scanning the sand for something pretty, a souvenir of my time in the sunshine.