I looked into it, seems like a cool thing to use to hide the wallet or private keys. Here is some sort of review:
http://www.pcworld.com/article/2026357/review-openpuff-steganography-tool-hides-confidential-data-in-plain-sight.htmlThe comment here said we need 3 images as carriers to hide a text file. So we may need much more files to hide a "wallet.dat"
http://www.softpedia.com/get/Authoring-tools/Authoring-Related/Puff.shtmlYou can use the application to conceal text files, images or other files with a maximum size of 256 MB. However, the size of the message greatly influences the number of carriers that need to be used. For instance, in order to send a short text file you need about three images as message carriers. For bigger files you need more carriers or bigger carriers that cannot be easily send by emails.