Water bottles and glow sticks make for perfect glow-in-th-dark backyard bowling pins. Make at least six of these, and use any kind of ball (basketball, soccer ball, etc.) to knock down your glowing pins.
So I thought about getting white balloons and putting blue and green glow sticks in them, then hang them upside down from the ceiling for the wedding. Definitely something that would need to be tried out before saying this is for sure what will be done.