You can use our ObjectiveFS[1] if you want a networked file system where multiple instances can simultaneously mount it read/write. It is backed by S3 and gives you a standard POSIX interface.
Thanks, interesting. Can you comment on how it compares to s3fs? I've used s3fs and it can sometimes be buggy (as in, to the point where files get clobbered and corrupted) and slow (especially in listing directories with a large number of files). Does ObjectiveFS solve these issues, and do you have any reliability statistics?