Glow-in-the-Dark Tap Water

"LED Tap Creates Glowing Water" GeekAlerts - Gadgets and Designs (March 14, 2008)

"This little device fits onto most taps and lights up a set of LEDs when you turn on the tap, transforming the stream of water into a beautiful waterfall of light."

I've posted something like this before: "Better Ideas From China: Color-Coded Shower Head Lights" (December 31, 2007).