Some gadgets are useful and some are just cool. The Faucet Light from Science Toy Store can be both. The blue Faucet Light is just cool. It is switched on by the pressure of flowing water and turns your water stream a pretty blue. The light turns off when the water flow stops. This light would be fun for kids of all ages. It’s $12.95. The two-color temperature-sensing Faucet Light is cool AND useful. The light is blue for cooler water and turns red when the temperature is at least 86 degrees. This light could help prevent kids from burning themselves or prevent someone like me from sticking my already icy-cold hands into cold water. The temperature-sensing light is $14.95. Both lights come with adapters that will fit most faucets; you should be able to install them yourself in a couple of minutes. Both also come with three extra batteries. Science Toy Store also has a battery-free temperature-sensing Shower Light for $37.99.