I just found that org-mac-iCal.el doesn't work on OS X 10.8 (Mountain Lion).
The trivial patch below fixes this. Cheers, -Steve commit 71b50131b5e6ae00a5e6c2f0bff2cec377c68c0f (HEAD, refs/heads/master) Author: Steve Purcell <st...@sanityinc.com> Date: Sat Dec 1 14:06:02 2012 +0000 org-mac-iCal: also use post-Leopard logic to concatenate calendars in 10.8 Modified contrib/lisp/org-mac-iCal.el diff --git a/contrib/lisp/org-mac-iCal.el b/contrib/lisp/org-mac-iCal.el index 0fdc95f..a48cf22 100644 --- a/contrib/lisp/org-mac-iCal.el +++ b/contrib/lisp/org-mac-iCal.el @@ -99,7 +99,7 @@ the the Emacs diary" ;; for each calendar, concatenate individual events into a single ics file (with-temp-buffer (shell-command "sw_vers" (current-buffer)) - (when (re-search-backward "10\\.[567]" nil t) + (when (re-search-backward "10\\.[5678]" nil t) (omi-concat-leopard-ics all-calendars))) ;; move all caldav ics files to the same place as local ics files