If, for any reason, you've ever showered in the dark, then you'll know just how wicked awesome this LED Shower Light is. From Think Geek, the shower-head-light ($40) fits your standard shower pipe. When you first turn on the shower, the light glows blue, indicating the water is chilly. When the light turns red, it means the water has heated up to a very comfortable 89 degrees. It installs in minutes and there's no batteries needed.