Looking for a way to have a portable filesystem (or mounting without root)
 

I have a free software project I'm working on that provides portable versions of Linux applications capable of being carried around on removable media, with settings and documents traveling along.

While developing the portable launcher, I fell into a problem: FAT32 partitions do not support symbolic links. This becomes a problem because 99% of Linux programs make use of symlinks for libraries, shared files, and whatnot. Therefore, I can solve the problem by duplicating directories where the symlinks would be, but this is extremely inefficient, and becomes a space problem on USB drives.

In my search for solutions, I thought of having a filesystem in a file that mounts into a temporary directory, from which the program then executes. The problem with this solution is that to mount a file, you require root privileges, and my target user base is users that will be using the apps on random computers, users that will not have root privileges on those computers.

My question is: Is it possible to have a read-write filesystem contained in a single file, and be able to mount it without root privileges? Maybe there is an alternative to mounting that accomplishes the same thing. Any ideas?

NOTE: Because of the situation, the users should not require root access on the host computers that they will be running apps on. It is safe to assume that they will have root access on the computers from which they will be downloading the apps from.

ANOTHER NOTE: I can't just use ext3 for the drive, because the portable apps will be for public use, and almost all removable media is either FAT or FAT32, neither of which support symlinks.

...sorry, posted about portools.com and then saw that you had actually posted in their forums, so advice was circular....

good luck with your quest - very interesting.

cheers,

Does the pendrive contain an entire linux system the user boots to, or are the users Linux users? Why can't you use ext2?