How can I get mouse selection to work in emacs and iTerm2 on Mac?

For Emacs in iTerm 2, I've found that the following bit in my ~/.emacs file works very well, providing the ability to insert the character at an arbitrary location, mark a region, and use the scroll wheel:

;; Enable mouse support
(unless window-system
  (require 'mouse)
  (xterm-mouse-mode t)
  (global-set-key [mouse-4] (lambda ()
                              (interactive)
                              (scroll-down 1)))
  (global-set-key [mouse-5] (lambda ()
                              (interactive)
                              (scroll-up 1)))
  (defun track-mouse (e))
  (setq mouse-sel-mode t)
)

I put this in my .emacs:

(require 'mouse)
(xterm-mouse-mode t)
(defun track-mouse (e)) 
(setq mouse-sel-mode t)

and that seems to do the trick, and now a mouse click in a split changes focus to the split.

Note: I am using iterm2, and I found the info here: http://groups.google.com/group/iterm2-discuss/browse_thread/thread/8e1f2ee7db26c07d/17ac15e69c554998?show_docid=17ac15e69c554998&pli=1