Summer has been heating up, and with it, the requests from the kids for glasses of water. It's a fantastic habit to cultivate, since staying hydrated isn't always an automatic behavior. But the constant dishwashing from multiple cups ("Is that my cup or yours?") is both a nuisance and environmentally unfriendly. That's why this clever hack that personalizes cups and keeps them close to the water source is a great idea for families with little kids.