Numbered window shortcuts for Emacs
window-numbering-mode and use M-1 through M-0 to navigate.
If you want to affect the numbers, use window-numbering-before-hook or window-numbering-assign-func. For instance, to always assign the calculator window the number 9, add the following to your .emacs:
(setq window-numbering-assign-func (lambda () (when (equal (buffer-name) "*Calculator*") 9)))