The nearest I can think of is the INCOMING directory on public FTP servers, which are generally public write-only; you can't read anything in there nor get a directory listing.
Peter [link|http://www.ubuntulinux.org|Ubuntu Linux] [link|http://www.kuro5hin.org|There is no K5 Cabal] [link|http://guildenstern.dyndns.org|Home] Use P2P for legitimate purposes!