[nzlug] computer read/write access to paper?

[Karl.]

Every now and then there are small files (encryption keyfiles) that I'd
like to store in some robust offline fashion.  I have a vague
recollection of software to print out a file as a 2D barcode, and then
something to read it back from a scan of the page.  Anyone here got any 
pointers on how to do this?

Vague thoughts:  I could hack up my own method by choosing a subset of 
characters which are consistently well recognized by ordinary OCR
software.  eg.  don't use Q because it looks too much like O, etc.  I
could just map my data onto the reduced character set, fold in some
forward error correction, and then just print it in a nice sans-serif 
font.  Good clean fun.

It'd be nice to use something that someone else had done the work for,
though - this isn't really the most important project to be sinking my
time into  :-)

I could also just write my keyfiles to CDR and store them somewhere
safe, but where's the fun in that?

Karl.