The DoD distro comes with a fixed set of applications, none of which should require writing to the program files during use. If you can keep the document you make from being infected, there's shouldn't be a problem with saving it back onto the thumb drive, to a second thumb, or to your hard drive.

If you write the Mini OS to a CD, it shouldn't be possible for any malware to write there to change the programs and if it actually works "in a secure way" having the program on a thumb drive shouldn't be very much of a risk.

It's probably not the way you want to go for a general purpose OS on a machine where you want lots of additional installed goodies, but as a "pocket OS" for use in unsecure places (like your city library or at Barnes on "free wifi"?) it might be a handy "accessory OS" for travel and temporary use(?). I'm not sure it has enough "bulit in" program capability to take to your buddy's machine when you have to help with a cleanup; but it's possible that you could add "clean accessories" to the thumb drive or CD you carry the OS on.

Off the subject: Newest threat - A malware researcher has demonstrated that some Mac BATTERIES can be hacked to insert malware onto any machine they're plugged into - and/or to make the batteries explode and burn up the machine(?). Ain't Evil Cute?

John