When I use windows and outlook I have a add-in installed siptapi :-
that allows me to use the Outlook address book to dial from my FPBX system, in summary it sends a request to the selected phone, then when you answer it places the outbound call for you, quite useful at times.
More often than not these days I am using Mac OS rather than Windows and I just wondered if anyone had come across a similar solution to use the MacBook address book in the same way?