Balloons taped to a wall to resemble by bubbles. This would be awesome at a bridal shower or another kind of party with a champagne bar. Love this idea! Use pearlescent colors for an adult party and primary colors for a kids' party.
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.