>I still keep a FreeDOS install on most of my usb keys I carry around.

Ha ha, at one time, as a system engineer, I used to carry many essential free DOS / Windows / Unix software apps (including some small utilities that I wrote - for both DOS and Unix, in Turbo C / Unix C and shell) around with me, burned onto a few CDs, on the theory that you never know when you may need it, on some client's PC (I used to go to solve clients' software problems). And it often did turn out that one of those apps was needed and I used it to solve some of their computer problems.