Bottle Shaped Water Powered Clock
There are only two types of clocks in this world, those that need batteries to run and those that do not. These bottle shaped water-powered clocks are the ones that fall into the latter category. Instead of drawing power from batteries, these colorful clocks draw power from water, the same water that you and I need to drink everyday.
An eco-friendly water-powered clock like one of these are definitely more convenient than conventional ones that run on batteries because all it needs for it to continue telling the time is to pop off its cap and top-up the water in the bottle when the water level gets low; which is great, especially for a lazy guy like me who hates to run to the store just to grab a pack of batteries for my gadgets.
Another good thing apart from the convenience is that you can even do something extra on your part for Earth by topping it up with collected rainwater in place of tap water.