Robert A. Uhl

PaperBack is free software which enables you to print data onto paper and read it back in via a scanner. With a 600 dpi printer and a 900 dpi scanner it is possible to store ½ megabyte of data per letter page; with compression, it’s possible to store about 3 megabytes per page (depending on the source data, of course — his example uses C code).

This is actually kinda cool: you could print out a few hundred pages and replicate the data on a CD; esp. with some oppressive regimes it may be easier to move physical objects that appear to be books than those which appear to contain data …