The backup files that emacs litters your filesystem with
can be a real pain. Stupid tilde files can be annoying and dangerous.
Especially since ~ does double duty of
being a short cut for your home directory. (I can't be the only
person who has accidently typed rm -fr *~ as
rm -fr * ~).
Anyway, the easy solution is to add this to your config file:
(setq backup-directory-alist '(("" . "~/.emacs.d/emacs-backup")))