Jun 01, '06 07:29:00AM • Contributed by: JaxMyers
$ mkdir ~/.Trash/iPhoto-Originals
$ cd ~/"Pictures/iPhoto Library/Modified/"
$ find . -type f -exec mv "../Originals/{}" ~/.Trash/iPhoto-Originals/ \;
This set of commands creates a folder called iPhoto-Originals in the trash, and moves all of the originals to the trash, while keeping the non-modified originals in place. Just ignore the errors that show up in Terminal; they have to do with the fact that there are some photos in the modified folder (such as movie thumbnails) which don't have corresponding originals.
Credit goes to RicardoL for the solution.
[robg adds: For those who don't know how iPhoto works, whenever you modify a photo, iPhoto keeps a copy of the original, so you can always revert your changes. If you use this script, you'll save some drive space, but you won't be able to revert your changes any more. And as noted, please make sure you have a current iPhoto library backup before trying this hint -- there's nothing worse than losing a bunch of digital photos that exist in no other form!]
