Hi Fein, thanks for the tip. I noticed the speedbar tree, and it's adequate.. but I'd rather like a nice Cocoa tree like in Alloy's MacVim port https://github.com/alloy/macvim/wiki/Screenshots instead of a NERDtree like speedbar.

Ahh, then what you want is ECB.

http://ecb.sourceforge.net/

and a screenie: http://kasun04.files.wordpress.com/2008/08/emacs1.jpg