Foldscope, The 50 Cent Microscope

A Stanford bioengineer develops a fully functional, ultra low-cost paper microscope. Wow.

From Scopeblog:

When Manu Prakash, PhD, wants to impress lab visitors with the durability of his Origami-based paper microscope, he throws it off a three-story balcony, stomps on it with his foot and dunks it into a water-filled beaker. Miraculously, it still works.
Even more amazing is that this microscope -- a bookmark-sized piece of layered cardstock with a micro-lens -- only costs about 50 cents in materials to make.

Stanford Bioengineer Develops A 50-Cent Paper Microscope