Instead of putting that info on a flash drive, why not just create a gmail account and e-mail the documents to it?

If you want other people to have access to some of it, you could just get a little dog tag engraved with the name of the g-mail account and the password and put that on your key ring. Something like "Medical information at xyz@gmail, password 1234"

You could, of course, encrypt your banking records or whatnot if you don't want people to have access to those.

I have a gmail account set up and tied to my PLB and I send updates to that account re my travel plans, etc. so if my PLB is activated rescuers can access that info in my g-mail account.

The only downside I can see is that it would not work where people do not have internet access or if the internet is no longer functioning. But I think chances are pretty good that anyone with a computer with a USB drive can figure out a way to get onto the internet. Heck, even if not, they could just call someone and have them access the internet and read them the medical info.