Whilst I wouldn't say this was the most glamorous piece of technology ever invented, it certainly is interesting for one simple reason - one being that it's very eco-friendly to run as it's powered by water. All you need to do is add water to the reservoir and within minutes you get a digital clock and alam. It's super cheap on sale at £4.99.
Related: Water powered clock I Water powered calculator I Eco-friendly gadgets

From: Five reasons Foursquare will be this year's Twitter