The Mini Hydro Clock is a small clock (about 2.5cm by 5cm) which simply displays the time. No alarm function, no date or calendar information. Just the time.
However, what is interesting is that you can power it with any fluid you like, including water, juice, milk and beer. I imagine that the smell from the milk when it goes off will be pretty nasty though! Considering you can use almost any water-based solution to power the clock without batteries…. you could use urine too!
Source: Geek Alerts