Sure, the world’s full of unusual clocks, both analog and digital, but this unusual design from Instructables user duckcrazy caught my eye for the many clever ways in which it makes the most of some common materials. The case is made from carefully-chosen 2-liter soda bottles, and the clock itself from a pair of CDs, a couple of print-and-fold paper cylinders, and an inexpensive analog clock movement. It’s an entry in Instructables currently-ongoing Clocks Challenge.