You would be crazy not to want a Citrus Powered Clock. I mean, seriously! It is powered by a lemon and it keeps time!
Unfortunately, it isn’t for sale — yet. Otherwise I’d snap one up. Designed by Florian Dussopt + Julie Girard. The wooden plank has two spikes of copper and zinc built into it. Reportedly, a single lemon will for your digital clock about one or two weeks.