There will be a time in every Mac user’s life where they will have duplicate images in their iPhoto library. I am aware that when importing images into iPhoto, there is an option to skip duplicates, but this only works while importing, not after the pictures have been imported. When I had to restore my iPhoto library from my external drive, iPhoto grabbed my originals folder and the data folder. For some reason, this caused more duplicates than I could ever have imagined. I found a miraculous AppleScript-based application called iPhoto Diet which will safely remove the duplicates and place them in iPhoto’s trash or into a separate duplicates folder within iPhoto. Trust me, this is an application you want to keep around for that one time you’ll need it.