Allow user to create files but not edit/delete

[Colin Law]

Is there a way to setup permissions and ownership such that a user can
create new files in a particular directory, and can read existing
ones, but cannot edit or delete existing ones?  By giving ownership of
the directory and existing files to root,  with permissions 777 on the
directory and 774 on existing files, then the user has read-only
access to existing files and can create new files, but unfortunately
he can delete existing files and re-create them, hence effectively
editing them.  Is there any way around this?

Colin