This clock combines two things that make me happy: Lemon juice and more lemon juice. Perfect for frequent travelers, this clock basically runs itself without a single battery. Fill the tank with water and a splash of lemon, and this little guy will keep accurate time for 6-8 weeks before having to refill it.
I have absolutely no clue how water and lemon juice keeps it going, but I'm sure it involves ven diagrams, the first law of thermodynamics and Wikipedia.
You can buy the Bedol Water Clock here for $16. Try not to guzzle it while in the middle of a drunken stupor, okay tiger?