One less set of batteries to worry about on our next camping trip. In fact, this alarm clock works on water. Yep, you read that right. Water. The Drop Bedol Water Alarm Clock converts ions in the water into clean energy power, and the built-in memory chip remembers the time so you don’t have to reset the clock. The water doesn’t even need to be replaced for 6 whole months. Plus, the clock has a daily or hourly alarm. Truly amazing, and it comes in 5 cool colors.