SpriteMods has published their design for a DIY NAND flash reader.
When security-testing the ‘secure’ USB-sticks I got my hands on in the past, I needed a way to directly read the NAND-flash these sticks use to store the data on. For that, I created a quick hack: a NAND-reader consisting of a small PCB the flash had to be soldered on and a parallel port interface. There was no voltage conversion apart from some resistors to limit the current from the 5V parallel port to the 3.3V flash chip and the software was a horrific hack, but the contraption worked: I now had a tool to read out NAND flash, even if it was tied together with the solder and the software equivalent of lots of duckttape.
For the schematic and source code, visit SpriteMods.