Because i couldn’t find it:
I wrote an AppleScript and derived an OMC command to show image files of selected photos in iPhoto.
Place the “Show in Finder.scpt” in
select images in you iPhoto Library and go to your
Script Menu -> iPhoto Scripts -> Show in Finder
It works like the “Show in Finder” of iTunes for audio files, select the photos and right click on the selection -> “Show in Finder”