The only result of any import when I searched for this was from 2001.
In the intervening decade, have any tools/methods for mounting a tar file as a filesystem (perhaps utilizing fuse) been created?
If so, what are they, and how do they work?
In fact, it seems that at least with newer Ubuntu1 versions it is possible to simply
apt-get install archivemount. Then you can mount your archive as
archivemount [archive file] [mount point]
1: I tried in Ubuntu 13.04.
I had problems with large tar files or with tars containing many files, so I created my own alternative to archivemount: ratarmount.