Supermount is a pseudo-filesystem which manages filesystems on removable media like floppy disks and CD-ROMs. It frees you from need to manually mount and unmount media.
With supermount, you can change the disk in the drive whenever you want (with the obvious exception that you shouldn't do it when the filesystem is actively in use). You don't need to "cd" out of the directory first, and you don't need to tell the kernel what you're doing --- supermount will detect the media change automatically.
Supermount will automatically detect whether the media you are mounting is read-write or readonly, and if you mount a write-protected disk, then the subfs will be mounted as a readonly filesystem.
Supermount detects when you have finished activity on the subfs, and will flush all buffers to the disk before completing the operation. So, if you copy a file onto a supermounted floppy disk, the data will all be written to disk before the "cp" command finishes. When the command does complete, it will be safe to remove the disk.
http://supermount-ng.sourceforge.net/