We're explicitly talking about USB drives, so might there be a way to
access multtiple filesystems on a single USB drive without needing admin
access?

ciao,

der.hans
--

Yes, but you would have to modify their project. I am going out on a limn here but I am guessing I am the only hard core windows admin on the list. Lisa probably knows the internal security better then I and we may have a few programmers willing to work on it, but it is likely we can get "layered" fs driver without having admin access. You will have to use your own GUI to interact with the drive, not explorer, but it can be done.
But, you have to ask what your target is. Will 70% or more of the users in question have access to admin level privileges? If so why not just include the real FS drivers on a FAT16 partition?