The best thing I can think of is to close the database and use the built-in
OS backup utility or a 3rd party backup program. Some of the 3rd party
programs will come with an "open file option". I've heard good and bad
things about the reliability of that option. The best thing to do would be
to check the support newsgroups for the backup program and see what its
users are saying. If the open file option works, you wouldn't need to close
the database.
To make sure the database is closed before your scheduled backup you could
"kick" the users out of the database at a certain time of day. Pick a time
when the users shouldn't be there and have the database close itself if the
user forgot to close it before leaving.
