I really dig those expensive LED faucets that glow blue and red to warn you of the temp. Here's my review of the $20 nozzle attachment version. As you'd guess, I'm giving up a thing or two by skimping:
•The LED isn't variable: Once you hit 89 degrees or greater, the red LED switches on. Before that, its blue. And when your water isn't running the circuit opens and the light goes off.
•The piece is long, so if you've got a shallow sink basin, you're going to be annoyed.
•It'll runs an unspecified number of hours with three easily changed small button batteries.
•Comes with two adapters for different faucet sizes.
•That's not chrome. It's silverized plastic (the kind that chips). What do you expect for $20?
•The flow is superb, but unfocused. Ultimately, I couldn't justify this without a wide spray and stream mode, and an adjustable neck. Depending on your love for LEDs, though, YMMV.
LED Faucet [Thinkgeek]