I was actually doing it right Chris (require 'org-mac-protocol).  I hadn't noticed a typo.

On Mon, Jul 20, 2009 at 7:36 PM, Christopher Suckling <suckling.list@googlemail.com> wrote:
On Tue, Jul 21, 2009 at 12:04 AM, Greg Newman<greg@20seven.org> wrote:
> Hmm, Chris.
> No matter what I do I always get "Required feature `org-mac-protocol' was
> not provided" when I re-eval.  I can load-file fine but when I add it to my
> configs, before or after org-mode it always barks at me.
>

Urrrgh. Stupid typo, but I'd already evaled the buffer when testing
and didn't notice.

Last line should read:

(require 'org-mac-protocol)

NOT

(require 'org-mac-protocol.el)

Putting together updated release now...

C.