Water-powered alarm clock
The Bedol water clock has been around for a while, but the fact that it's cheap and seemingly useful landed it on this list. The $20 "Squirt" clock converts water's ions into clean energy power to keep the clock running. Fill the clock with water and it will last six months. It's a simple alarm clock, with one control panel for one alarm.
Lyndsey Gilpin has nothing to disclose. She doesn't hold investments in the technology companies she covers.
Lyndsey Gilpin is a former Staff Writer for TechRepublic, covering sustainability and entrepreneurship. She's co-author of the book Follow the Geeks.