;; emacsredux.com
(defun rename-file-and-buffer ()
  "Rename the current buffer and file it is visiting."
  (interactive)
  (let ((filename (buffer-file-name)))
    (if (not (and filename (file-exists-p filename)))
        (message "Buffer is not visiting a file!")
      (let ((new-name (read-file-name "New name: " filename)))
        (cond
         ((vc-backend filename) (vc-rename-file filename new-name))
         (t
          (rename-file filename new-name t)
          (rename-buffer new-name)
          (set-visited-file-name new-name)
          (set-buffer-modified-p nil)))))))

(defadvice ido-find-file (after find-file-sudo activate)
  "Find file as root if necessary."
  (unless (and buffer-file-name
               (file-writable-p buffer-file-name))
    (find-alternate-file (concat "/sudo:root@localhost:" buffer-file-name))))

(defun eval-and-replace ()
  "Replace the preceding sexp with its value."
  (interactive)
  (backward-kill-sexp)
  (condition-case nil
      (prin1 (eval (read (current-kill 0)))
             (current-buffer))
    (error (message "Invalid expression")
           (insert (current-kill 0)))))
(global-set-key (kbd "C-)") 'eval-and-replace)