Also, note that you can customize the Cocoa text environment to be pretty much straight Emacs keystrokes (it's already there, but you have to configure it). See http://www.hcs.harvard.edu/~jrus/Site/Cocoa%20Text%20System.... for a wonderful set of tips and hints.
It's heaven having Emacs editing commands in any web-based text widget (like this one), and everywhere else that's Cocoa-based text.