Researchers at the Fraunhofer Institute's Production Systems and Design Technology lab have created software designed to take scans of shredded documents and piece them back together. The scans are "analysed by a cluster of 16 computers for 25 features, including color, shape, texture, handwriting and typeface" and then pieced back together. Which is almost as effective as my method: guessing. And tape. Lots and lots of tape.