I blogged about fullscreen emacs yesterday. I decided to put my integrated repository online until the upstream maintainers decide to integrate typester's code.
You can get the code here:
git clone http://git.poffenberger.org/emacs.git
$ ./configure --with-ns $ make && make install $ mv nextstep/Emacs.app /Applications/
If you want a patch get it here or if you just want the binary, look here
As is usual in these cases, this code is covered by the terms of the GPL (see the license in the repository for the exact terms). Further, I make no personal guarantees about the code or the binary's fitness for any purpose. If it mulches your car don't call me! ;-)
1 Instructions courtesy of Steve Purcell. See Steve's blog post for the original. Typester did the original work to bring fullscreen to emacs on OS X.