Setting up a shared sftp file area

[Ben Williams]

This is probably a basic question but I'd like to set up a shared file
area on a remote machine where a group of users can upload files that
will be accessible to the other members of the group. I tried just
setting up a folder owned by the group but of course that doesn't work
because the uploaded files are owned by the user who uploaded them and
aren't accessible to the other users. I'd like some more secure than
ftp but I'll use it if that's the only easy way of doing this.

Thanks,
-Ben