Possible, yes, but I think scandisk will complain about lost clusters.

You mark the clusters as used, but don't associate a filename with them, you'll need a way to access the data though.

Hiding it in a 24 bit bmp file is quite cool, but a 24 bit bmp file stores 4 bytes for every pixel... like this:

HEADER 56? bytes
BGRrBGRrBGRr

Where BGR is Blue/Green/Red (in that order) and r is a reserved byte, not used at the moment. Perhaps for 32 bit color bmp's

In this way you can store the encrypted password file in your company's logo, noone will look for it there. You can also just compile the logo into a resource file and LoadRespource it, that way there won't even have to be a seperate file.

more info about image cryptography: www.blindside.co.uk