61:  How do I disable backup files?

  You probably don't want to do this, since backups are useful.

  If you're tired of seeing backup files whenever you do an "ls" at the
  Unix shell, try GNU ls with the "-B" option.  GNU ls is part of the GNU
  fileutils package, available at prep and its mirrors (see question 89).
  To avoid seeing backup files (and other "uninteresting" files) in Dired,
  use the omitting feature of dired-x.el, which comes with Emacs.

  To disable or change how backups are made, see "Backup Names" in the
  on-line manual.