Need different settings for different machines?

;; Settings for currently logged in user
(setq user-settings-dir
      (concat user-emacs-directory "users/" user-login-name))

;; Conclude init by setting up specifics for the current user
(when (file-exists-p user-settings-dir)
  (mapc 'load (directory-files user-settings-dir nil "^[^#].*el$")))

These are the last lines of my init.el. They will load any *.el files in the ~/.emacs.d/users/user-login-name/ folder.

Anything specific for that machine goes there.