Water—Powered Alarm Clock

"Half fill the right–hand tube with tap water, wait a few minutes, and the display will light up."

Very nicely done.

Who knew cold fusion had made its way into consumer products already?

Not me, that's for sure.

"Use the MODE and SET buttons to set the date and time and alarm function."

Measures 5.5" x 4.5" x 2.5".

"The clock will only need topping up about every two months."

$13.99 here.