Eshellをpopwinで ref: http://qiita.com/items/0939787fcd8fb9efbba1

my-eshell.el

(when (featurep 'popwin)
  (push '("*eshell*" :height 0.5) popwin:special-display-config)

  (defun eshell-pop (universal-argument)
    "open eshell window using popwin-elf"
    (interactive "P")
    (let* ((eshell-buffer-name "*eshell*")
       (eshell-buffer (get-buffer eshell-buffer-name))
       (file-name (buffer-file-name (current-buffer)))
       (current-directory (with-current-buffer (current-buffer) default-directory)))
      (if eshell-buffer
      (popwin:display-buffer eshell-buffer)
    (eshell))
      (when (and universal-argument file-name)
    (eshell-kill-input)
    (insert (concat "cd " current-directory))
    (eshell-send-input)
    (end-of-buffer))))
  (global-set-key "¥C-w¥C-w" 'eshell-pop))