BTW, I find that iPhoto is...Dunno the word...but I used to think that it's a sweet programme to organise my photos but quit using it weeks later. I do not understand how the database works, you will have duplicates in your library (not within iPhoto interface but in the library directory path), I remember vaguely, there'll be a folder called 'modify' and one 'original' and even has thumbnails of each photos and these clogs your drive space for no reason.