exporting/exposing directory over the Internet?

[Joachim Rosenfeld]

I wish to store some files on my FreeBSD 7 server that will be used by
various clients (FreeBSD, Windows, and Linux). What is a good way to
export a directory so that it can be mounted on various systems and
seen as a local directory?

NFS is out, for security reasons.

I was thinking of Samba, but I'm not sure of the security implications
of using it over the public Internet.

Somebody mentioned WebDAV, but I'm not familiar with it at all and I'm
not sure if it can do what I need it to do.

Any recommendations?