I have also seen similar centerpieces that use epsom salts instead of sugar. You could also sprinkle a mix of pearls/gems. Sand (or sugar), faux pearls, a 3 candle. An easy DIY wedding centerpiece idea.
Mini Fruit Pizza Bar: Let your guests make their own mini fruit pizzas. All you need is pre-baked sugar cookies, filling to spoon on jar marshmallow cream mixed with 8 oz block of cream cheese), and assorted fresh fruit.