Actually this has nothing to do with IT security, though the technique thought of by sharp guys from Princeton seems extraordinary. The research team made their way to identify fingerprints with help of a regular scanner:

This paper presents a novel technique for authenticating physical documents based on random, naturally occurring imperfections in paper texture. We introduce a new method for measuring the three-dimensional surface of a page using only a commodity scanner and without modifying the document in any way. From this physical feature, we generate a concise fingerprint that uniquely identifies the document. Our technique is secure against counterfeiting and robust to harsh handling; it can be used even before any content is printed on a page. It has a wide range of applications, including detecting forged currency and tickets, authenticating passports, and halting counterfeit goods. Document identification could also be applied maliciously to de-anonymize printed surveys and to compromise the secrecy of paper ballots.

Curious pictures publicized by Ed Felton in his blog. It is always challenging to give another life to common things we are surrounded by, similarly we suggested an alternative implementation of video cards and successfully use this technology to speed up password recovery. Inventive minds!